Resolve "gitlab:setup rake task fails on 8.8.1 source install"

_Originally opened at !4788 by @rickettm._

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## What does this MR do?

Fix bug #15344, so that the limit parameter that is already passed in to the print_users function is actually used, rather than using a hardcoded value.

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

No, it is a trivial change.

## Why was this MR needed?

This bug causes 100 LDAP users to be displayed even when a different limit is given, which can be annoying.

## What are the relevant issue numbers?

Fixes #15344.

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5364