QmlDesigner: Crash Fix

We somehow managed to raise a more general exception.
There is no reason to not play safe.

Change-Id: I44ff0d6c3e5181e1c067b1b5d6620cd6a8723d27
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/plugins/qmldesigner/components/stateseditor/stateseditorview.cpp

@@ -274,7 +274,7 @@ void StatesEditorView::setWhenCondition(int internalNodeId, const QString &condi
             if (state.isValid())
                 state.modelNode().bindingProperty("when").setExpression(condition);
 
-        } catch (const RewritingException &e) {
+        } catch (const Exception &e) {
             e.showException();
         }
     }