Fix different warnings

[ovalseven8]

Bug Description

Warning

``` ARIA: Attribute " aria-label ", required for accessibility, is missing on node: button.md-icon-button.md-button.md-ink-ripple ​ accessKey: "" ​ accessKeyLabel: "" ​ assignedSlot: null ​ attributes: NamedNodeMap(10) [ class="md-icon-button md-button md-ink-ripple", type="button", ng-transclude="", … ] ​ autofocus: false ​ baseURI: "https://web-beta.threema.ch/#!/messenger/conversation/contact/*SUPPORT" ​ childElementCount: 1 ​ childNodes: NodeList(3) [ #text, md-icon.ng-scope.material-icons, #text ] ​ children: HTMLCollection [ md-icon.ng-scope.material-icons ] ​ classList: DOMTokenList(3) [ "md-icon-button", "md-button", "md-ink-ripple" ] ​ className: "md-icon-button md-button md-ink-ripple" ​ clientHeight: 0 ​ clientLeft: 0 ​ clientTop: 0 ​ clientWidth: 0 ​ contentEditable: "inherit" ​ contextMenu: null ​ dataset: DOMStringMap(0) ​ dir: "" ​ disabled: false ​ draggable: false ​ firstChild: #text " " ​ firstElementChild: ​ form: null ​ formAction: "https://web-beta.threema.ch/#!/messenger/conversation/contact/*SUPPORT" ​ formEnctype: "" ​ formMethod: "" ​ formNoValidate: false ​ formTarget: "" ​ hidden: false ​ id: "" ​ innerHTML: "\n \n " ​ innerText: "\n \n " ​ isConnected: false ​ isContentEditable: false ​ labels: NodeList [] ​ lang: "" ​ lastChild: #text " " ​ lastElementChild: ​ localName: "button" ​ name: "" ​ namespaceURI: "http://www.w3.org/1999/xhtml" ​ nextElementSibling: null ​ nextSibling: #text " " ​ ng339: undefined ​ nodeName: "BUTTON" ​ nodeType: 1 ​ nodeValue: null ​ offsetHeight: 0 ​ offsetLeft: 0 ​ offsetParent: null ​ offsetTop: 0 ​ offsetWidth: 0 ​ onabort: null ​ onanimationcancel: null ​ onanimationend: null ​ onanimationiteration: null ​ onanimationstart: null ​ onauxclick: null ​ onblur: null ​ oncanplay: null ​ oncanplaythrough: null ​ onchange: null ​ onclick: null ​ onclose: null ​ oncontextmenu: null ​ oncopy: null ​ oncut: null ​ ondblclick: null ​ ondrag: null ​ ondragend: null ​ ondragenter: null ​ ondragexit: null ​ ondragleave: null ​ ondragover: null ​ ondragstart: null ​ ondrop: null ​ ondurationchange: null ​ onemptied: null ​ onended: null ​ onerror: null ​ onfocus: null ​ onfullscreenchange: null ​ onfullscreenerror: null ​ ongotpointercapture: null ​ oninput: null ​ oninvalid: null ​ onkeydown: null ​ onkeypress: null ​ onkeyup: null ​ onload: null ​ onloadeddata: null ​ onloadedmetadata: null ​ onloadend: null ​ onloadstart: null ​ onlostpointercapture: null ​ onmousedown: null ​ onmouseenter: null ​ onmouseleave: null ​ onmousemove: null ​ onmouseout: null ​ onmouseover: null ​ onmouseup: null ​ onmozfullscreenchange: null ​ onmozfullscreenerror: null ​ onpaste: null ​ onpause: null ​ onplay: null ​ onplaying: null ​ onpointercancel: null ​ onpointerdown: null ​ onpointerenter: null ​ onpointerleave: null ​ onpointermove: null ​ onpointerout: null ​ onpointerover: null ​ onpointerup: null ​ onprogress: null ​ onratechange: null ​ onreset: null ​ onresize: null ​ onscroll: null ​ onseeked: null ​ onseeking: null ​ onselect: null ​ onselectstart: null ​ onshow: null ​ onstalled: null ​ onsubmit: null ​ onsuspend: null ​ ontimeupdate: null ​ ontoggle: null ​ ontransitioncancel: null ​ ontransitionend: null ​ ontransitionrun: null ​ ontransitionstart: null ​ onvolumechange: null ​ onwaiting: null ​ onwebkitanimationend: null ​ onwebkitanimationiteration: null ​ onwebkitanimationstart: null ​ onwebkittransitionend: null ​ onwheel: null ​ outerHTML: "\n \n " ​ ownerDocument: HTMLDocument https://web-beta.threema.ch/#!/messenger/conversation/contact/*SUPPORT ​ parentElement: ​ parentNode: ​ prefix: null ​ previousElementSibling: null ​ previousSibling: #text " " ​ scrollHeight: 0 ​ scrollLeft: 0 ​ scrollLeftMax: 0 ​ scrollTop: 0 ​ scrollTopMax: 0 ​ scrollWidth: 0 ​ shadowRoot: null ​ slot: "" ​ spellcheck: false ​ style: CSS2Properties(0) ​ tabIndex: 0 ​ tagName: "BUTTON" ​ textContent: "\n \n " ​ title: "Unterhaltung ist nicht angepinnt. Klicken, um sie anzupinnen." ​ type: "button" ​ validationMessage: "" ​ validity: ValidityState { valueMissing: false, typeMismatch: false, patternMismatch: false, … } ​ value: "" ​ willValidate: false ​ : HTMLButtonElementPrototype { checkValidity: checkValidity(), reportValidity: reportValidity(), setCustomValidity: setCustomValidity(), … } ```

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Ein iframe, der sowohl "allow-scripts" als auch "allow-same-origin" für sein "sandbox"-Attribut gesetzt hat, kann seine Sandbox entfernen.

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onmozfullscreenchange sollte nicht mehr verwendet werden.
onmozfullscreenerror sollte nicht mehr verwendet werden.

Your Environment

• Threema Web version: Version 2.2.0-beta.3 Glärnisch
• Threema App version: 4.0-beta2 (Android)
• Browser name and version: Firefox 67.0.4

[dbrgn]

ARIA: Attribute " aria-label ", required for accessibility, is missing on node:

We do set aria-label, albeit dynamically. This is a false positive.

onmozfullscreenchange sollte nicht mehr verwendet werden. onmozfullscreenerror sollte nicht mehr verwendet werden.

Those don't come from our own source code.

Ein iframe, der sowohl "allow-scripts" als auch "allow-same-origin" für sein "sandbox"-Attribut gesetzt hat, kann seine Sandbox entfernen.

We don't use iframes. Context?