[server] NotADirectoryError does not exist on py2x, use IOError instead

beat/editor/resources.py

@@ -140,7 +140,7 @@ def generate_file_tree(entity, config):
     assert_valid_entity(entity)
     resource_path = os.path.join(config.path, entity)
     if not os.path.isdir(resource_path):
-        raise NotADirectoryError('Invalid resource path %s' % resource_path)
+        raise IOError('Invalid resource path %s' % resource_path)
 
     return path_to_dict(resource_path)
 
@@ -304,7 +304,7 @@ def gen_endpoint(entity):
             """Regenerates the entity tree"""
             try:
                 return generate_entity_tree(entity, self.config)
-            except NotADirectoryError:
+            except IOError:
                 return []
 
         def get(self):