HOT-FIX: Issue with changes with the language file name (#466)

* HOT-FIX: Issue with changes with the language file name

* Rubocop!

app/controllers/application_controller.rb

@@ -45,7 +45,7 @@ class ApplicationController < ActionController::Base
 
   def update_locale(user)
     I18n.locale = if user && user.language != 'default'
-      user.language
+      user.language.tr('-', '_')
     else
       http_accept_language.language_region_compatible_from(I18n.available_locales)
     end

app/helpers/sessions_helper.rb

@@ -64,7 +64,7 @@ module SessionsHelper
   end
 
   def parse_user_domain(hostname)
-    return hostname.split('.').first unless Rails.configuration.url_host
+    return hostname.split('.').first if Rails.configuration.url_host.empty?
     Rails.configuration.url_host.split(',').each do |url_host|
       if hostname.include?(url_host)
         return hostname.chomp(url_host).chomp('.')