fix file path

What does this MR do?

Fix the file path to a default Nginx file that needs to be deleted for the GitLab web gui to be browsed. Changing it from:

/etc/sites-enabled/default

to

/etc/nginx/sites-enabled/default

Are there points in the code the reviewer needs to double check?

If we are expecting older versions than Ubuntu 16.04 with Nginx 1.10.0 to be the most common use case for a 7.14 source install, then maybe Nginx used to create this file in the place where the README says and in that case we would leave it.

The tests are failing but it can't be because of this change

Why was this MR needed?

When trying to install V7.14 from source on Ubuntu 16.04 with Nginx 1.10.0, the README says to delete a file that exists in a different place from where the README points to.

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Tests
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with 7-14-stable (if you do - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #7 (closed)