Merge branch 'ldap-fixes' into 'master'

Ldap fixes

Solves #1688 and #1686

See merge request !1193

config/initializers/1_settings.rb

@@ -61,7 +61,6 @@ Settings.ldap['enabled'] = false if Settings.ldap['enabled'].nil?
 if Settings.ldap['enabled'] || Rails.env.test?
   if Settings.ldap['host'].present?
     server = Settings.ldap.except('sync_time')
-    server['label'] = 'LDAP'
     server['provider_name'] = 'ldap'
     Settings.ldap['servers'] = {
       'ldap' => server
@@ -69,6 +68,7 @@ if Settings.ldap['enabled'] || Rails.env.test?
   end
 
   Settings.ldap['servers'].each do |key, server|
+    server['label'] ||= 'LDAP'
     server['allow_username_or_email_login'] = false if server['allow_username_or_email_login'].nil?
     server['active_directory'] = true if server['active_directory'].nil?
     server['provider_name'] ||= "ldap#{key}".downcase

config/initializers/7_omniauth.rb

 if Gitlab::LDAP::Config.enabled?
   module OmniAuth::Strategies
     server = Gitlab.config.ldap.servers.values.first
-    const_set(server['provider_class'], Class.new(LDAP))
+    klass = server['provider_class']
+    const_set(klass, Class.new(LDAP)) unless klass == 'LDAP'
   end
 
   OmniauthCallbacksController.class_eval do