[bindings] root.quit overrides help_menu.quit

[loralb]

Hello! Thank you very much for your work!

The title pretty much says it all, the value set in help_menu.quit is ignored (both the default one and a custom one), because it is overriden by whatever the value in root.quit is (both if changing this binding to a custom one and if leaving the default value).

EDIT:
gitu --version -> gitu 0.25.0
System: Archlinux

[altsem]

@loralb do you have a use-case to bind help_menu.quit and root.quit to different keys?
I'm considering doing something about the duplication of these in #257

[loralb]

I really like navigating through the various modes/menus/pop-ups by simply typing q or esc, but more than once I accidently closed the application by typing it one too many times. Basically, my use case is to use the defualt bindings for everything excpet for exiting gitu, for which I prefer something "more complex" (for example, I set it to ctrl+q for now).