The rollback link next to an entry in your watchlist and in a contributions list
for a page move should rollback the page move. Currently the rollback link has
no effect as it just attempts to rollback the null edit. To rollback the page
move you have to use the link from the page move log.
This will make the behaviour inline with what you expect a rollback button to do
- rollback the change.
(see also bug T5185 that I guess may be easy to fix at the same time as this one)