camera control: do not save ftp downloaded xml file twice

src/Camera/QGCCameraControl.cc

@@ -2056,6 +2056,7 @@ void QGCCameraControl::_ftpDownloadComplete(const QString& fileName, const QStri
         return;
     }
 
+    _cached = true;
     QByteArray bytes = xmlFile.readAll();
     emit dataReady(bytes);
 }

src/Camera/QGCCameraManager.cc

@@ -112,7 +112,6 @@ QGCCameraManager::_handleHeartbeat(const mavlink_message_t &message)
     mavlink_heartbeat_t heartbeat;
     mavlink_msg_heartbeat_decode(&message, &heartbeat);
     //-- First time hearing from this one?
-    qCDebug(CameraManagerLog) << "Another Hearbeat from " << message.compid;
     QString sCompID = QString::number(message.compid);
     if(!_cameraInfoRequest.contains(sCompID)) {
         qCDebug(CameraManagerLog) << "Hearbeat from " << message.compid;