Don't cancel sending "seen" messages on MQTT enabled nodes (#2690)

src/mesh/FloodingRouter.cpp

@@ -21,7 +21,7 @@ bool FloodingRouter::shouldFilterReceived(const meshtastic_MeshPacket *p)
 {
     if (wasSeenRecently(p)) { // Note: this will also add a recent packet record
         printPacket("Ignoring incoming msg, because we've already seen it", p);
-        if (config.device.role != meshtastic_Config_DeviceConfig_Role_ROUTER &&
+        if (!moduleConfig.mqtt.enabled && config.device.role != meshtastic_Config_DeviceConfig_Role_ROUTER &&
             config.device.role != meshtastic_Config_DeviceConfig_Role_ROUTER_CLIENT &&
             config.device.role != meshtastic_Config_DeviceConfig_Role_REPEATER) {
             // cancel rebroadcast of this message *if* there was already one, unless we're a router/repeater!