Release memory of the contact acl before unloading module

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@237135 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -19612,6 +19612,7 @@ restartdestroy:
 
 	clear_realm_authentication(authl);
 	clear_sip_domains();
+	ast_free_ha(global_contact_ha);
 	close(sipsock);
 	sched_context_destroy(sched);