Check for OkToMqtt flag presence before uplinking to MQTT (#5413)

* Check for oktomqtt flag presence before uplinking to MQTT

* Move to mqtt->onSend

src/mqtt/MQTT.cpp

@@ -545,9 +545,11 @@ void MQTT::onSend(const meshtastic_MeshPacket &mp_encrypted, const meshtastic_Me
 
     // mp_decoded will not be decoded when it's PKI encrypted and not directed to us
     if (mp_decoded.which_payload_variant == meshtastic_MeshPacket_decoded_tag) {
+        // For uplinking other's packets, check if it's not OK to MQTT or if it's an older packet without the bitfield
+        bool dontUplink = !mp_decoded.decoded.has_bitfield ||
+                          (mp_decoded.decoded.has_bitfield && !(mp_decoded.decoded.bitfield & BITFIELD_OK_TO_MQTT_MASK));
         // check for the lowest bit of the data bitfield set false, and the use of one of the default keys.
-        if (!isFromUs(&mp_decoded) && !isMqttServerAddressPrivate && mp_decoded.decoded.has_bitfield &&
-            !(mp_decoded.decoded.bitfield & BITFIELD_OK_TO_MQTT_MASK) &&
+        if (!isFromUs(&mp_decoded) && !isMqttServerAddressPrivate && dontUplink &&
             (ch.settings.psk.size < 2 || (ch.settings.psk.size == 16 && memcmp(ch.settings.psk.bytes, defaultpsk, 16)) ||
              (ch.settings.psk.size == 32 && memcmp(ch.settings.psk.bytes, eventpsk, 32)))) {
             LOG_INFO("MQTT onSend - Not forwarding packet due to DontMqttMeBro flag");