Require Qt5.

common/camera.cpp

@@ -126,11 +126,7 @@ void lcCamera::CreateName(const lcArray<lcCamera*>& Cameras)
 		if (CameraName.startsWith(Prefix))
 		{
 			bool Ok = false;
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 0, 0))
 			int CameraNumber = CameraName.midRef(Prefix.size()).toInt(&Ok);
-#else
-			int CameraNumber = CameraName.mid((int)strlen(Prefix.latin1())).toInt(&Ok);
-#endif
 
 			if (Ok && CameraNumber > MaxCameraNumber)
 				MaxCameraNumber = CameraNumber;