Fixed .desktop and appdata file

[susnux]

Fixed .desktop-file according to https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html

• Removed BOM from .desktop
• Set correct version in .desktop (version is the version of the Desktop Entry Specification not of the application)
• Encoding is deprecated (always UTF-8)
• Set correct Icon name (the name should not contain an file extension)

Fixed invalid xml of appdata file

• Removed invalid xml tag (there was no opening tag) from appdata

[susnux]

Noticed this errors when building for openSUSE, RPMLint errors without this patch are:

[  846s] vdrift.x86_64: W: invalid-xml-in-appdata /usr/share/appdata/vdrift.appdata.xml
[  846s] The appdata file provided by the package is not valid XML and will cause
[  846s] problems. Use e.g. xmllint to verify the problem and fix.
[  846s] 
[  846s] vdrift.x86_64: W: invalid-desktopfile /usr/share/applications/vdrift.desktop value "2012-07-22" for key "Version" in group "Desktop Entry" is not a known version
[  846s] vdrift.x86_64: W: invalid-desktopfile /usr/share/applications/vdrift.desktop (will be fatal in the future): value "vdrift.png" for key "Icon" in group "Desktop Entry" is an icon name with an extension, but there should be no extension as described in the Icon Theme Specification if the value is not an absolute path
[  846s] .desktop file is not valid, check with desktop-file-validate