tests/test-gendoc-sv.t

absorb: improve message for the case when changeset became empty

In changeset f55099982bc5, I introduced the message "became empty and became
...", which I was never very happy with. Raphaël Gomès suggested "became empty
as ...". That sounds much nicer.

Differential Revision: https://phab.mercurial-scm.org/D8765

#require docutils gettext

  $ $TESTDIR/check-gendoc sv
  checking for parse errors