pidgin/pidgin

handle GTK_RESPONSE_DELETE_EVENT when closing account manager via window manager

Testing Done:
Ran Pidgin and closed the account manager with the X button of the window manager.

Reviewed at https://reviews.imfreedom.org/r/1515/
PURPLE_HISTORY_SOURCES = [
'purplehistorycore.c',
]
purple_history = executable('purple-history',
PURPLE_HISTORY_SOURCES,
dependencies : [libpurple_dep, glib],
install : true)