tests/narrow-library.sh

resolve: respect ui.relative-paths also for warning messages

I guess this should have been part of 72a9aacff645 (resolve: respect
ui.relative-paths, 2019-01-29).

Differential Revision: https://phab.mercurial-scm.org/D5937

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