The NoMore404s menu does not automatically close after clicking an option

[SoftVision-CosminMuntean]

[Affected versions]:

• Nightly 54.0a1
• NoMore404s 1.7.1

[Affected Platforms]:

• All Windows
• All Mac
• All Linux

[Prerequisites]:

• Latest NoMore404s add-on (v1.7.1) was previously installed on a new profile.

[Steps to reproduce]:

1. Open the browser with the profile from prerequisite and navigate to any website.
2. Click the NoMore404s icon from the browser toolbar.
3. Click any option from the doorhanger menu.
4. Observe the doorhanger menu behaviour.

[Expected result]:

• The doorhanger menu is automatically closed.

[Actual result]:

• The doorhanger menu is still displayed even after the option is performed.

[Notes]:

• Attached a screen recording with the issue: https://goo.gl/OiiPyJ

[SoftVision-EmilPasca]

Because of this, the "URL not found in wayback archives!" alert is displayed when clicking twice the "First Version" button for a page.

[Affected versions]:

• Nightly 54.0a1
• NoMore404s 1.8.1

[Affected Platforms]:

• All Windows
• All Mac
• All Linux

[Prerequisites]:

• Latest NoMore404s add-on (v1.8.1) was previously installed on a new profile.

[Steps to reproduce]:

1. Open the browser with the profile from prerequisite.
2. Navigate to any website (eg. https://www.theguardian.com).
3. Click the "NoMore404s" button and choose the "First Version" option.
4. While the new opened tab is loading, click again on the "First Version" button.

[Expected result]:

• The doorhanger menu is automatically closed after the first click.

[Actual result]:

• An alert is displayed showing the "URL not found in wayback archives!" message, after the second click.

[Notes]:

• The same behavior can be observed for the "Recent Version" option.
• Attached a screen recording of the issue: