app_queue: Fix a bug where realtime members would be deleted during reload causing waiting callers to get ejected.

This patch causes realtime queue members to remain in queues during the reload process. Previously these
members would be removed causing any waiting callers to be ejected from the queue with a reason of "EXITEMPTY".

ASTERISK-23547 #close
ASTERISK-23547 #comment Patch app_queue_fix_realtime_reload_1.8_trunk.patch submitted by Italo Rossi (license 6409)

Review: https://reviewboard.asterisk.org/r/3404/


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/1.8@411584 f38db490-d61c-443f-a65b-d21fe96a405b