server/comments: fix serializing cached scores

server/szurubooru/db/comment.py

@@ -35,7 +35,8 @@ class Comment(Base):
 
     @property
     def score(self):
-        return object_session(self) \
+        from szurubooru.db import session
+        return session \
             .query(func.sum(CommentScore.score)) \
             .filter(CommentScore.comment_id == self.comment_id) \
             .one()[0] or 0

server/szurubooru/tests/api/test_comment_rating.py

@@ -33,7 +33,6 @@ def test_simple_rating(test_ctx, fake_datetime):
             test_ctx.context_factory(input={'score': 1}, user=user),
             comment.comment_id)
     assert 'text' in result
-    comment = db.session.query(db.Comment).one()
     assert db.session.query(db.CommentScore).count() == 1
     assert comment is not None
     assert comment.score == 1