Prevent xorm nil insert in Review.Comments (#11150)

models/review.go

@@ -457,10 +457,12 @@ func InsertReviews(reviews []*Review) error {
 			c.ReviewID = review.ID
 		}
 
+		if len(review.Comments) > 0 {
 			if _, err := sess.NoAutoTime().Insert(review.Comments); err != nil {
 				return err
 			}
 		}
+	}
 
 	return sess.Commit()
 }