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
cat >> $HGRCPATH <<EOF
[extensions]
narrow=
[ui]
ssh=python "$RUNTESTDIR/dummyssh"
[experimental]
changegroup3 = True
EOF