Regression error in calculate reactive cache of Environment model

We merged !85105 (diffs) to fix #350729 (closed) .

But error.error_code is not available for Gitlab::UrlBlocker::BlockedUrlError.

Errors noticed in logs: https://log.gprd.gitlab.net/goto/afd212b0-c174-11ec-afaf-2bca15dfbf33

Proposal:

Escape the unavailable error method with try.

error.try(:error_code)