Fix local_resource_url usage

mentoring/mentoring.py

@@ -208,8 +208,10 @@ class MentoringBlock(XBlockWithLightChildren):
             'self': self,
             'xml_content': self.xml_content or self.default_xml_content,
         }))
-        fragment.add_javascript(self.runtime.local_resource_url('public/js/mentoring_edit.js'))
-        fragment.add_css(self.runtime.local_resource_url('public/css/mentoring_edit.css'))
+        fragment.add_javascript_url(
+            self.runtime.local_resource_url(self, 'public/js/mentoring_edit.js'))
+        fragment.add_css_url(
+            self.runtime.local_resource_url(self, 'public/css/mentoring_edit.css'))
 
         fragment.initialize_js('MentoringEditBlock')