Settings code loop in some circumstances

This is pretty obscure but I have been hitting a code loop and / or exit when the browser is returned from paying IF there is a setting.get api call in the hook hit on return Under wordpress on a domain other then number 1 (where 2 exist).

I don't fully understand why but the issue is appearing in some deprecated code and the code logic appears to be incorrect.

```
if ($domainID != CRM_Core_Config::domainID())

{ $reloadConfig = TRUE; CRM_Core_BAO_Domain::setDomain($domainID); }

```

Sets the domain if there is a mismatch. This code is marked as deprecated & related to the config_backend setting - which is now gone. More notably the reverse of this function is

CRM_Core_BAO_Domain::resetDomain();

It is this function that the code is never returning from

From recollection this logic was primarily introduced for the purposes of unit testing across multiple domains - and the code comments say

```

/**

• Change active domain (ie. to perform a temporary action) such as changing
• config for all domains
  *
• Switching around the global domain variable is very risky business. This
• is ONLY used as a hack to allow CRM_Core_BAO_Setting::setItems to manipulate
• the civicrm_domain.config_backend in multiple domains. When/if config_backend
• goes away, this hack should be removed.
  *
• @param int $domainID
• Id for domain you want to set as current.
• @deprecated
• @see http://issues.civicrm.org/jira/browse/CRM-11204
  */
  ```

My patch does not go the full hog on removing this - it simply ensures that resetDomain is not called if the other is not called - however, my sense is that the test coverage here is thorough enough we could fully remove it.