pidgin/pidgin

g_task_return_* refs a task so we need to make sure we remove our reference when we're done with the task.

Testing Done:
Compiled and connected to bonjour and xmpp locally.

Reviewed at https://reviews.imfreedom.org/r/470/
pidgin3_xml = configure_file(
input : 'pidgin3.xml.in',
output : 'pidgin3.xml',
configuration : version_conf,
install : true,
install_dir : get_option('datadir') / 'glade/catalogs')