service: Do not change default service if new default is not connected

It is possible that we have already decided to change the default
gateway in connection.c but the service is still in configuration
state. In this case just return -EINPROGRESS and do nothing.
The default service will be changed in service_indicate_state()
a bit later anyway.

src/service.c

@@ -5326,7 +5326,16 @@ int __connman_service_clear_error(struct connman_service *service)
 
 int __connman_service_indicate_default(struct connman_service *service)
 {
-	DBG("service %p", service);
+	DBG("service %p state %s", service, state2string(service->state));
+
+	if (!is_connected(service)) {
+		/*
+		 * If service is not yet fully connected, then we must not
+		 * change the default yet. The default gw will be changed
+		 * after the service state is in ready.
+		 */
+		return -EINPROGRESS;
+	}
 
 	default_changed();