tests/test-issue1102.t

rebase: delete obsolete internal "keepopen" option

The option was apparently introduced for use by the "pbranch"
extension, see f2558a8228be (rebase: add option to not commit after a
collapsing, 2010-02-07). However, it doesn't seem like it was ever
used by that extension (according to `hg grep` in a clone of
https://bitbucket.org/parren/hg-pbranch/), so let's delete it.

Differential Revision: https://phab.mercurial-scm.org/D2708

  $ rm -rf a
  $ hg init a
  $ cd a
  $ echo a > a
  $ hg ci -Am0
  adding a
  $ hg tag t1 # 1
  $ hg tag --remove t1 # 2

  $ hg co 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg tag -f -r0 t1
  $ hg tags
  tip                                3:a49829c4fc11
  t1                                 0:f7b1eb17ad24

  $ cd ..