Bug 21751: (follow-up) Correction to selectors

Bug 21751: (follow-up) Correction to selectors

This patch makes a couple of corrections to the selectors used by
hcsticky in targeting the position of the floating toolbar. These
changes were made necessary by changes made in recently-pushed patches.

To test, confirm that these two pages work correctly:

 - Acquisitions -> Vendor -> View basket
 - Patrons -> New patron

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>