convert: inline strutil.rfindall()
This is the only place where strutil is used. I don't think it's worth to
keep the strutil module, so inline it.
Also, strutil.rfindall() appears to have off-by-one error. 'end = c - 1' is
wrong because 'end' is exclusive.
#
# Avoid interference from actual test env:
unset HGTEST_JOBS
unset HGTEST_TIMEOUT
unset HGTEST_PORT
unset HGTEST_SHELL