Number of total repositories shown for GitLab ACLs

Created by: attfarhan

• Sourcegraph version: dev build

Steps to reproduce:

1. Make sure you have at least 1 repo you aren't able to access on a GitLab instance.
2. Go to the /site-admin/repositories page
3. See that the total number of repositories appears as matching, even if you only have viewer rights to a subset of the total repositories.

Expected behavior: Should not show total number of matches if I don't have access to all repos.

Actual behavior: Shows total number of matches even if I don't have access to all repos.