QmlDesigner: Disable validator in any case

We have to disable the validator even if the root node has no id.

Change-Id: I021c33909dfa7c3aa3154d1782a589cef9151af5
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/plugins/qmldesigner/qmldesignerextension/connectioneditor/delegates.cpp

@@ -321,6 +321,7 @@ QWidget *ConnectionDelegate::createEditor(QWidget *parent, const QStyleOptionVie
                 connectionComboBox->addItem(itemText, source);
             }
         }
+        connectionComboBox->disableValidator();
     } break;
 
     default: qWarning() << "ConnectionDelegate::createEditor column" << index.column();