Revert "Merge branch '499487/restricted-ip' into 'master'"

Purpose of revert

Incident: 500 HTTP Error accessing snippets via API (#511501 - closed)

This reverts merge request !175332 (merged)

Postgres raises an error like when users tries to access snippets

ERROR:  invalid cidr value: "111.11.11.11/22" (PG::InvalidTextRepresentation)
DETAIL:  Value has bits set to right of mask.

Sentry error: https://new-sentry.gitlab.net/organizations/gitlab/issues/1271536

Checklist

• Create an issue to reinstate the merge request and assign it to the author of the reverted merge request.
• If the revert is to resolve a broken 'master' incident, please read through the Responsibilities of the Broken master resolution DRI.
• If the revert involves a database migration, please read through Deleting existing migrations.
• Add the appropriate labels before the MR is created. We can skip CI/CD jobs only if the labels are added before the CI/CD pipeline is created.

Milestone info

• I am reverting something in the current milestone. No changelog is needed, and I've added a ~"regression:*" label.
• I am reverting something in a different milestone. A changelog is needed, and I've removed the ~"regression:*" label.

Related issues and merge requests