hotfix: set QOpenGLDebugLogger to synchronous mode to enable stacktraces

when breaking on glerror

widgets/glWidget/QtBaseViewer_qt.cc

@@ -102,7 +102,7 @@ void glViewer::startGLDebugLogger()
     if (glDebugLogger_->initialize())
     {
       connect(glDebugLogger_, SIGNAL(messageLogged(QOpenGLDebugMessage)), this, SLOT(processGLDebugMessage(QOpenGLDebugMessage)));
-      glDebugLogger_->startLogging();
+      glDebugLogger_->startLogging(QOpenGLDebugLogger::SynchronousLogging);
     }
   }
 #endif