Fix for new keycloak version

yellow/auth.py

@@ -10,6 +10,8 @@ from yellow.models import User
 @keycloak.after_login()
 async def handle_user_login(auth_token: KeycloakAuthToken):
     username = auth_token.username
+    uid = auth_token.sub
+
     if not re.match(r"^[a-zA-Z0-9_\.-]+$", username):
         raise Exception("bad username")