Hide project activity tabs when features are disabled

## What does this MR do?

When features are disabled in project settings, the activity tabs are now correctly hidden.

## Screenshots (if relevant)

![Screen_Shot_2016-10-21_at_12.15.27](/uploads/3d85c027aa05487001c8abd624a99be0/Screen_Shot_2016-10-21_at_12.15.27.png)

## What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/19734#note_17224181

See merge request !7038