Draft: Remove restrictions on reindexing rake task (not for merging)

What does this MR do and why?

Remove restrictions on reindexing rake task

To be provided to a customer for local patching

• issue: #474639
• ticket:
  • https://gitlab.zendesk.com/agent/tickets/535599
  • https://support.gitlab.com/hc/en-us/requests/535599

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