Remove unused import (fixes #398)

Author: DavidMStraub

gramps_webapi/auth/__init__.py

@@ -28,7 +28,6 @@
 import sqlalchemy as sa
 from flask_sqlalchemy import SQLAlchemy
 from sqlalchemy.exc import IntegrityError, StatementError
-from sqlalchemy.orm import mapped_column, relationship
 from sqlalchemy.sql.functions import coalesce
 
 from ..const import DB_CONFIG_ALLOWED_KEYS