Don't remove SUUpdater as KVO observer, because the ones that are observing are singletons and are never deallocated, while temporary instances cannot remove themselves as observer because they're not registered.
Don't remove SUUpdater as KVO observer, because the ones that are observing are singletons and are never deallocated, while temporary instances cannot remove themselves as observer because they're not registered.

git-svn-id: 765db44a9620ed55f4f8addfd3c14fe8cd57f6bb@5575 0fceea05-a30d-0410-8a8b-80ef821fb0a1

nanoant/Skim,nanoant/Skim,nanoant/Skim,nanoant/Skim,nanoant/Skim