CRM-14489 - Removed protocol from language domain if it exists.

On a Drupal multilingual site if the "Language Domain" setting of the current Drupal locale contains the protocol then the function languageNegotiationURL in CRM_Utils_System_Drupal.php duplicates it.

Without this fix then for an input $url = "https://domain.com" and $language->domain = "https://domain.com" it will return "https://https://domain.com"