Fix MQTT reconnect behavior

mgos_mqtt_global_connect() should kick off reconnect if needed, too.

PUBLISHED_FROM=c8f4d07fb46fc2b4a7e39fcebf7cc0e9c2cc022a

Author: Deomid Ryabkov

src/mgos_mqtt.c

@@ -384,16 +384,15 @@ bool mgos_mqtt_global_connect(void) {
     mg_set_protocol_mqtt(s_conn);
     s_conn->recv_mbuf_limit = s_cfg->recv_mbuf_limit;
   } else {
+    mqtt_global_reconnect();
     ret = false;
   }
   return ret;
 }
 
 static void reconnect_timer_cb(void *user_data) {
   s_reconnect_timer_id = MGOS_INVALID_TIMER_ID;
-  if (!mgos_mqtt_global_connect()) {
-    mqtt_global_reconnect();
-  }
+  mgos_mqtt_global_connect();
   (void) user_data;
 }