tests/test-issue1089.t

tests: fix up some import statements caught by Python 3

I'm curious how the import checker manages to be so much more
pedantic in Python 3, but not enough to bother exploring.

Differential Revision: https://phab.mercurial-scm.org/D5240

https://bz.mercurial-scm.org/1089

  $ hg init
  $ mkdir a
  $ echo a > a/b
  $ hg ci -Am m
  adding a/b

  $ hg rm a
  removing a/b
  $ hg ci -m m a

  $ mkdir a b
  $ echo a > a/b
  $ hg ci -Am m
  adding a/b

  $ hg rm a
  removing a/b
  $ cd b

Relative delete:

  $ hg ci -m m ../a

  $ cd ..