[#29240] Undefined property: $registeredurlparams

[#29240] Undefined property: $registeredurlparams

This is hopefully the 3.x fix for:
http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=29240

and:
https://github.com/joomla/joomla-cms/pull/425