FINDPRODUCT property was not available to this deferred custom action.
Not to mention that registry keys are also deleted at his stage of uninstallation.
The proper solution is to set the installation directory with a type 51 custom action,
and pass it to RemoveExtensions custom action via CustomActionData property.

Change-Id: I0ac18b3a0b19ff1a87bcf580fad9c7fdadb26f76