Fixes #333.
I cannot reproduce this crash, but looks like the crash happens during
exit, I am thinking perhaps the buddylist window gets closed before the
plugin tries to remove the statusboxes.
#
# pidgin_major_ver and pidgin_minor_ver should be defined to match the minimum
# Pidgin API version _required_ to build Plugin Pack
# Due to the way Pidgin checks plugin versions, we need to also ensure that
# the correct minimum version of Pidgin is Require:'d based on what version of