build: One more compiler flag
Revert "window: Workaround mismatch in GAction and GtkAction accelerators"

This reverts commit fd5399bd4ac81d9a57e55c5b8411a9217ee0355b.
accels: Sync app and menu accelerators

When porting to using gtkapplication accelerators, there was a regression
in that the in-menu accelerators were not changed/disabled accordingly, which
meant that they were still being activated even when the global accelerator
was disabled.

https://bugzilla.gnome.org/show_bug.cgi?id=728121