fix:null error

Author: anj20

mslib/mscolab/migrations/versions/6c44d67e505a_to_version_11_0_0.py

@@ -21,13 +21,15 @@ def upgrade():
     # ### commands auto generated by Alembic - please adjust! ###
     with op.batch_alter_table('users', schema=None) as batch_op:
         batch_op.add_column(sa.Column('profile_image_path', sa.String(length=255), nullable=True))
-
+    op.alter_column('changes', 'version_name', existing_type=sa.String(255), nullable=True)
+    op.alter_column('changes', 'comment', existing_type=sa.String(255), nullable=True)
     # ### end Alembic commands ###
 
 
 def downgrade():
     # ### commands auto generated by Alembic - please adjust! ###
     with op.batch_alter_table('users', schema=None) as batch_op:
         batch_op.drop_column('profile_image_path')
-
+    op.alter_column('changes', 'version_name', existing_type=sa.String(255), nullable=False)
+    op.alter_column('changes', 'comment', existing_type=sa.String(255), nullable=False)
     # ### end Alembic commands ###