Text of editing comment in QnA topics appears after cancelling edit and trying re-edit

Precondition: user should have edit_own_post permission; user should have comment in QnA topic.

Steps to reproduce:

1. Open QnA topic with user's comment to post in it.
2. Click 'Edit comment' button.
3. Make some changes to comment and click 'Cancel' - comment without editing is displayed.
4. Click 'Edit comment' button.

Actual result: in comment field edited comment is displayed.
Expected result: in comment field comment without editing is displayed.