Enable zmqnotify only on non-proxy.

src/stratifier.c

@@ -8796,6 +8796,7 @@ void *stratifier(void *arg)
 		create_pthread(&pth_statsupdate, statsupdate, ckp);
 
 	mutex_init(&sdata->share_lock);
+	if (!ckp->proxy)
 		create_pthread(&pth_zmqnotify, zmqnotify, ckp);
 
 	ckp->stratifier_ready = true;