Fix EZP-22426: DetectMobileDevice redirection fails for URI

Link: https://jira.ez.no/browse/EZP-22426

## Description
When using an URI in `MobileSiteAccessURL` the feature would not work as expected.

Examples of expected behaviors:

| URL entered | URL redirected |
| ----------------- | ----------- |
| http://ez4.local | http://ez4.local/iphone |
| http://ez4.local/eng | http://ez4.local/iphone/ |
| http://ez4.local/blog | http://ez4.local/iphone/blog |
| http://ez4.local/eng/blog | http://ez4.local/iphone/blog |


## Test
Manual test using firefox user agent switcher