Fix EZP-21636: Hinclude sub-requests are broken since EZP-21631 fix

https://jira.ez.no/browse/EZP-21636

Fixes a regression from d6e3f67

Since Symfony 2.3.5, `$absolute` has been added to `generateFragmentUri()` (see [EZP-21631](https://jira.ez.no/browse/EZP-21631) and https://github.com/symfony/symfony/issues/8458). When I fixed EZP-21631, I just forgot to pass this new argument to the parent method.

`$absolute` is a boolean indicating if we want to generate an ablsoute fragment link.