Fix the class loader when updating the updater

It used the wrong parent class loader, and as a consequence, no new
updater was used at all!

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
While at it, bump the parent

We have to release a rather dramatic bug fix for the updater in one big
hurry anyway, so let's just add this innocuous change at the same time.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Bump to next development cycle

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>