QGCCameraManager: Move from QTime to QElapsedTimer to avoid deprecated functions

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

src/Camera/QGCCameraManager.h

@@ -91,7 +91,7 @@ protected:
     class CameraStruct : public QObject {
     public:
         CameraStruct(QObject* parent, uint8_t compID_);
-        QTime   lastHeartbeat;
+        QElapsedTimer lastHeartbeat;
         bool    infoReceived = false;
         bool    gaveUp       = false;
         int     tryCount     = 0;
@@ -105,8 +105,8 @@ protected:
     QmlObjectListModel  _cameras;
     QStringList         _cameraLabels;
     int                 _currentCamera      = 0;
-    QTime               _lastZoomChange;
-    QTime               _lastCameraChange;
+    QElapsedTimer       _lastZoomChange;
+    QElapsedTimer       _lastCameraChange;
     QTimer              _cameraTimer;
     QMap<QString, CameraStruct*> _cameraInfoRequest;
 };