Unable to add/edit column comments

### Version Information

Server Version: 2.1.1

### Environment

OSS

### What is the expected behaviour?

I should be able to edit or add new column comments.

### What is the current behaviour?

Can't add or modify column comments.

### How to reproduce the issue?

1. Track a table.
2. Edit a column.
3. Put some text in the 'comment' box
4. click "save"
5. get an error

### Screenshots or Screencast