app: Take default modifiers into account
app: Take default modifiers into account

When checking for particular modifier bit in a key event, we must take
into acount any default modifiers that might be set on the event's state:

https://developer.gnome.org/gtk3/stable/checklist-modifiers.html

This fixes CTRL+Q and ALT+A keyboard shortcuts not working anymore.

Thanks to David Kind and Paolo Borelli for pointing this out.

https://bugzilla.gnome.org/show_bug.cgi?id=706415

vbenes/gnome-boxes,vbenes/gnome-boxes