pidgin/pidgin

Clean up some random gtk-doc warnings in libpurple's documentation

Testing Done:
Ran `ninja libpurple-doc` locally, verified the warnings went away.

Reviewed at https://reviews.imfreedom.org/r/585/
REVIEWBOARD_URL = "https://reviews.imfreedom.org/"
REPOSITORY = "pidgin/pidgin"
REPOSITORY_TYPE = "mercurial"
BRANCH = "default"
LAND_DEST_BRANCH = "default"
LAND_PUSH = False