mq: clean up unused variable in qrefresh
Removes the unused variable `aa2` that holds the list of deleted files
returned from repo.status().
http://mercurial.selenic.com/bts/issue433
$ hg init
$ echo a > a
$ hg commit -Ama
adding a
$ hg parents -r 0 doesnotexist
abort: 'doesnotexist' not found in manifest!
[255]