Rename rack_attack.rb initializer

Merged Mayra Cabrera requested to merge 218291-rename-rack-attack-config-file into master

What does this MR do?

Rename rack_attack.rb initializer

RackAttack config file was renamed to 'rack_attack_new.rb' so it was able to co-exists with the Omnibus settings (for more info see gitlab-foss!31246 (comment 215110463))

Since the Omnibus RackAttack settings were removed on 13.0, we can rename this initializer back to its original name.

Related to #218291 (closed)

Does this MR meet the acceptance criteria?

Conformity

Availability and Testing

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

  • [-] Label as security and @ mention @gitlab-com/gl-security/appsec
  • [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
  • [-] Security reports checked/validated by a reviewer from the AppSec team

Related to #218291 (closed)