Merge pull request #58 in TPSH/ckanext-odsh from master to dev

* commit 'c0b69d23':
  Revert "makes license attribution optional"

ckanext/odsh/plugin.py

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