Fix hidden click handles on Templates

- on some Templates, the green click handles for
  editing text were being painted under the Template
  and were not visible.

src/Mod/TechDraw/Gui/TemplateTextField.cpp

@@ -40,7 +40,9 @@ TemplateTextField::TemplateTextField(QGraphicsItem *parent,
     : QGraphicsRectItem(parent),
       tmplte(myTmplte),
       fieldNameStr(myFieldName)
-{ }
+{
+    setToolTip(QObject::tr("Click to update text"));
+ }
 
 void TemplateTextField::mousePressEvent(QGraphicsSceneMouseEvent *event)
 {