run-tests: fix conditional when tests are run outside of `tests`
The logic to find `hghave` was using `__file__` but… non absolute path in
`__file__` gets wrong as soon as we change directory (thanks python… you are
being helpful). The rest of the `run-tests.py` code already deal with this
fine. We simply reuse the `RUNTESTDIR` variable to fix it.
Issue351: mq: qrefresh can create extra revlog entry
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init
$ hg qinit
$ echo b > b
$ hg ci -A -m foo
adding b
$ echo cc > b
$ hg qnew -f foo.diff
$ echo b > b
$ hg qrefresh
$ hg debugindex b
rev linkrev nodeid p1 p2
0 0 1e88685f5dde 000000000000 000000000000