DB: Upravena points_history i v ORMu

mo/db.py

@@ -439,7 +439,7 @@ class PointsHistory(Base):
     points_history_id = Column(Integer, primary_key=True, server_default=text("nextval('points_history_points_history_id_seq'::regclass)"))
     task_id = Column(Integer, ForeignKey('tasks.task_id'), nullable=False)
     participant_id = Column(Integer, ForeignKey('users.user_id'), nullable=False)
-    points = Column(Integer, nullable=False)
+    points = Column(Integer)
     points_by = Column(Integer, ForeignKey('users.user_id'), nullable=False)
     points_at = Column(DateTime(True), nullable=False)