pidgin/pidgin

Update PidginProtocolStore to use the icon-name rather than GdkPixbuf

Testing Done:
Opened the new account window and verified that the protocol icons were still working

Reviewed at https://reviews.imfreedom.org/r/1323/
syntax: glob
.*.swp
.DS_Store
.flatpak-builder
*.pyc
*~
\#*\#
syntax: regexp
^build(.+)?\/
win32-install-dir(\.release)?
po\/pidgin\.pot$
^subprojects\/.+\/