🐛 Don't return 0 if successful packet sent with QoS 0

Author: marvinroger

docs/2.-API-reference.md

@@ -135,7 +135,7 @@ Return the packet ID or 0 if failed.
 
 Publish a packet.
 
-Return the packet ID or 0 if failed.
+Return the packet ID (or 1 if QoS 0) or 0 if failed.
 
 * **`topic`**: Topic
 * **`qos`**: QoS

src/AsyncMqttClient.cpp

@@ -712,5 +712,6 @@ uint16_t AsyncMqttClient::publish(const char* topic, uint8_t qos, bool retain, c
   _client.send();
   _lastClientActivity = millis();
 
-  return packetId;
+  if (qos != 0) return packetId;
+  else return 1;
 }