tests/narrow-library.sh

match: fix doctest to use bytes instead of str

Fixes doctests on Python 3.

Differential Revision: https://phab.mercurial-scm.org/D5423

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