start render-thread with normal priority on win32 as otherwise the whole GUI is almost frozen

git-svn-id: https://lmms.svn.sf.net/svnroot/lmms/trunk/lmms@1690 0778d3d1-df1d-0410-868b-ea421aaaa00d

src/core/project_renderer.cpp

@@ -130,7 +130,11 @@ void projectRenderer::startProcessing( void )
 		engine::getMixer()->setAudioDevice( m_fileDev,
 						m_qualitySettings, FALSE );
 
-		start( QThread::HighestPriority );
+		start(
+#ifndef LMMS_BUILD_WIN32
+			QThread::HighPriority
+#endif
+						);
 	}
 }