tests/helper-runtests.sh

revlog: move check for wdir from changelog to revlog

Yuya said he preferred this (to keep them in one place, I think).

Differential Revision: https://phab.mercurial-scm.org/D569

#
# Avoid interference from actual test env:

unset HGTEST_JOBS
unset HGTEST_TIMEOUT
unset HGTEST_PORT
unset HGTEST_SHELL