bring back single AOR (#112)

kamailio/registrar-role.cfg

@@ -245,7 +245,7 @@ route[CHECK_AUTHORIZATION]
 
 route[SAVE_LOCATION]
 {
-    $var(save_result) = save("location");
+    $var(save_result) = save("location", "0x04");
     if($var(save_result) == -1) {
         auth_challenge("$fd", "0");
         xlog("L_INFO", "$ci|end|issued auth challenge after failed attempt to save contact for $Au $si:$sp\n");