Can't edit or remove a comment if the user isn't the one that created the topic

[ane-gabriela]

Steps to reproduce:

1. Log in as a simple user
2. Create a forum
3. Create a topic
4. Add an answer
5. Add a comment
6. Observe the buttons available
7. Log in as another user
8. Add a comment
9. Observe the buttons available

Expected results: The users can edit and remove the comments added by themselves.

Actual results: The user that isn't the creator of the Topic can only edit and remove his answer but not the comments.

Environment: Windows 10, IE 11, XWiki 10.10 with MySQL 5.7