pidgin/pidgin

Add a settings property to PurpleCredentialProvider that is a GSettings object

Testing Done:
Ran the unit tests. However I didn't add this to the tests because adding a dummy settings object is more trouble than it's worth.

Reviewed at https://reviews.imfreedom.org/r/2145/
syntax: glob
.*.swp
.DS_Store
.flatpak-builder
*.pyc
*~
\#*\#
syntax: regexp
^build(.+)?\/
win32-install-dir(\.release)?
po\/pidgin\.pot$
^subprojects\/.+\/