mod_conference: don't transfer back to the same conference

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@13638 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/mod/applications/mod_conference/mod_conference.c

@@ -3933,6 +3933,7 @@ static switch_status_t conf_api_sub_transfer(conference_obj_t *conference, switc
 
 			/* move the member from the old conference to the new one */
 			switch_mutex_lock(member->control_mutex);
+			if (conference != new_conference) {
 				conference_del_member(conference, member);
 				conference_add_member(new_conference, member);
 
@@ -3944,6 +3945,7 @@ static switch_status_t conf_api_sub_transfer(conference_obj_t *conference, switc
 						switch_set_flag_locked(member, MFLAG_RESTART);
 					}
 				}
+			}
 
 			switch_mutex_unlock(member->control_mutex);