Remove extra gitlab_rails['omniauth_enabled'] flags

doc/integration/bitbucket.md

@@ -89,8 +89,6 @@ you to use.
    For Omnibus packages:
    ```ruby
-   gitlab_rails['omniauth_enabled'] = true
-
    gitlab_rails['omniauth_providers'] = [
      {
        "name" => "bitbucket",

doc/integration/kerberos.md

@@ -72,7 +72,6 @@ For source installations, make sure the `kerberos` gem group
 1. Edit `/etc/gitlab/gitlab.rb`:
    ```ruby
-   gitlab_rails['omniauth_enabled'] = true
    gitlab_rails['omniauth_allow_single_sign_on'] = ['kerberos']
    gitlab_rails['kerberos_enabled'] = true

doc/integration/omniauth.md

@@ -80,9 +80,6 @@ To change these settings:
   and change:
   ```ruby
-  # Versions prior to 11.4 require this to be set to true
-  # gitlab_rails['omniauth_enabled'] = nil
-
   # CAUTION!
   # This allows users to login without having a user account first. Define the allowed providers
   # using an array, e.g. ["saml", "twitter"], or as true/false to allow all providers or none.

doc/integration/saml.md

@@ -37,7 +37,6 @@ in your SAML IdP:
    For Omnibus package:
    ```ruby
-   gitlab_rails['omniauth_enabled'] = true
    gitlab_rails['omniauth_allow_single_sign_on'] = ['saml']
    gitlab_rails['omniauth_block_auto_created_users'] = false
    ```

doc/integration/shibboleth.md

@@ -71,7 +71,6 @@ The following changes are needed to enable Shibboleth:
    gitlab_rails['omniauth_allow_single_sign_on'] = true
    gitlab_rails['omniauth_block_auto_created_users'] = false
-   gitlab_rails['omniauth_enabled'] = true
    gitlab_rails['omniauth_providers'] = [
      {
        "name"  => "'shibboleth"',