pidgin/pidgin

Remove PurpleProtocolClient->tooltip_text as it is barely used and we're scaling back our tooltip usage

Testing Done:
Compiled

Reviewed at https://reviews.imfreedom.org/r/2370/
syntax: glob
.*.swp
.DS_Store
.flatpak-builder
*.pyc
*~
\#*\#
syntax: regexp
^build(.+)?\/
win32-install-dir(\.release)?
po\/pidgin\.pot$
^subprojects\/.+\/