makes license attribution optional

ckanext/odsh/plugin.py

@@ -111,7 +111,6 @@ class OdshPlugin(plugins.SingletonPlugin, DefaultTranslation, DefaultDatasetForm
         schema['extras'].update({
             'key': [
                 toolkit.get_converter('known_spatial_uri'),
-                toolkit.get_converter('validate_licenseAttributionByText'),
             ]
         })
         schema.update(