Dismiss commit msg key

[wessamfathi]

This Pull Request fixes/closes #2552.

It changes the following:

• The default key to close the commit error message popup is now the Escape key

I followed the checklist:

• I added unittests
• I ran make check without errors
• I tested the overall application
• I added an appropriate item to the changelog

[naseschwarz]

I tested this and the escape key works.

[naseschwarz]

The command legend is still set to Enter, though:

You probably also want to update MsgPopup::commands, replace strings::commands::close_msg by strings::commands::close_popup.

[wessamfathi]

Good catch. I submitted a fix.

[naseschwarz]

Thank you for the change. I tested it again. It still works fine and displays the correct symbol in the legend.