tests/test-1102

fix test-mq-eol under --pure (mimic diffhelper.c behaviour)

bug discovered by apycot (apycot.hg-scm.org)

#!/bin/sh

rm -rf a
hg init a
cd a
echo a > a
hg ci -Am0
hg tag t1 # 1
hg tag --remove t1 # 2

hg co 1
hg tag -r0 t1
hg tags