exception handling in plotter

source/RobotAPI/gui-plugins/SensorActorWidgetsPlugin/ArmarXPlotter/ArmarXPlotter.cpp

@@ -723,6 +723,10 @@ namespace armarx
         {
             ARMARX_WARNING << deactivateSpam(5) << "Caught InvalidChannelException: " << e.what();
         }
+        catch (armarx::UserException& e)
+        {
+            ARMARX_WARNING << deactivateSpam(5) << "Caught UserException: " << e.what() << "\nReason: " << e.reason;
+        }
         catch (...)
         {
             handleExceptions();