Only give the insufficient subproxy message when looking for a global proxy

src/stratifier.c

@@ -2902,6 +2902,7 @@ static sdata_t *select_sdata(const ckpool_t *ckp, sdata_t *ckp_sdata, const int
 	mutex_unlock(&ckp_sdata->proxy_lock);
 
 	if (!best) {
+		if (!userid)
 			LOGWARNING("Temporarily insufficient subproxies to accept more clients");
 		return NULL;
 	}