CSP: disable LFS url when not using object storage

What does this MR do and why?

CSP: disable LFS url when not using object storage

Disable the allow_lfs when object storage is not enabled for LFS.

1. When using local storage, the path will come from within GitLab's primary URL
2. When using local storage, Fog/CarrierWave will fail, unless user always supplies a bogus connection hash.
   • Omnibus leave this empty unless provided.

Related to #422936 (closed)

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Configure gitlab.yml with CSP enabled, and LFS enabled without object storage.

   production:
     gitlab:
       content_security_policy:
         enabled: true
         report_only: true
     lfs:
       enabled: true
       object_store:
         enabled: false
         remote_directory: 'lfs-objects'
         connection: {}
         direct_upload: false
         proxy_download: true
         storage_options: {}

2. Rails / Puma start successfully

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.