Use encryption instead of method

The method key is deprecated in the `gitlab_omniauth-ldap` gem.

lib/gitlab/ldap/config.rb

@@ -50,7 +50,7 @@ module Gitlab
       def omniauth_options
         opts = base_options.merge(
           base: base,
-          method: options['method'],
+          encryption: options['encryption'],
           filter: omniauth_user_filter,
           name_proc: name_proc
         )
@@ -158,7 +158,7 @@ module Gitlab
       end
 
       def encryption
-        case options['method'].to_s
+        case options['encryption'].to_s
         when 'ssl'
           :simple_tls
         when 'tls'

spec/lib/gitlab/ldap/config_spec.rb

@@ -25,7 +25,7 @@ describe Gitlab::LDAP::Config, lib: true do
         options: {
           'host'       => 'ldap.example.com',
           'port'       => 386,
-          'method'  => 'plain'
+          'encryption' => 'plain'
         }
       )
 
@@ -41,7 +41,7 @@ describe Gitlab::LDAP::Config, lib: true do
         options: {
           'host'       => 'ldap.example.com',
           'port'       => 686,
-          'method'    => 'ssl',
+          'encryption' => 'ssl',
           'bind_dn'    => 'uid=admin,dc=example,dc=com',
           'password'   => 'super_secret'
         }
@@ -67,7 +67,7 @@ describe Gitlab::LDAP::Config, lib: true do
           'host'       => 'ldap.example.com',
           'port'       => 386,
           'base'       => 'ou=users,dc=example,dc=com',
-          'method'  => 'plain',
+          'encryption' => 'plain',
           'uid'        => 'uid'
         }
       )
@@ -76,7 +76,7 @@ describe Gitlab::LDAP::Config, lib: true do
         host: 'ldap.example.com',
         port: 386,
         base: 'ou=users,dc=example,dc=com',
-        method: 'plain',
+        encryption: 'plain',
         filter: '(uid=%{username})'
       )
       expect(config.omniauth_options.keys).not_to include(:bind_dn, :password)