form: translate "Add row" of WidgetList (#11070)

wcs/qommon/form.py

@@ -1274,6 +1274,20 @@ class CaptchaWidget(CompositeWidget):
         return r.getvalue()
 
 class WidgetList(quixote.form.widget.WidgetList):
+    def __init__(self, name, value=None,
+                 element_type=StringWidget,
+                 element_kwargs={},
+                 add_element_label="Add row", **kwargs):
+
+        if add_element_label == 'Add row':
+            add_element_label = _('Add row')
+
+        super(WidgetList, self).__init__(name, value=value,
+                element_type=element_type,
+                element_kwargs=element_kwargs,
+                add_element_label=add_element_label, **kwargs)
+
+
     def render(self):
         get_response().add_javascript(['jquery.js', 'widget_list.js'])
         r = TemplateIO(html=True)