remove raise statement which was just needed for debugging

common/lib/xmodule/xmodule/modulestore/mongo.py

@@ -76,7 +76,6 @@ class CachingDescriptorSystem(MakoDescriptorSystem):
                     module.inherit_metadata(metadata_to_inherit)
                 return module
             except:
-                raise
                 return ErrorDescriptor.from_json(
                     json_data,
                     self,