fix infofasjson get_user_attrs returning None

Previously if using the fasjson info plugin, and the fasjson client
returned an error, we were returning None. However, we need to return an
empty dict, otherwise login/common.py in ipsilon would raise an error.

Signed-off-by: Ryan Lerch <rlerch@redhat.com>

ipsilon/info/infofasjson.py

@@ -48,7 +48,7 @@ Info plugin that retrieves user data from FASJSON. """
             user_agreements_data = client.list_user_agreements(username=user).result
         except Exception as e:
             self.error(f'FASJSON error: {e}')
-            return
+            return {}
 
         # assumption that first email is the default
         user_data['email'] = user_data['emails'][0]