test-convert-git: remove the read-only attribute of repository files
Git object files are stored read-only in the filesystem. Trying to remove a
read-only file on windows will fail with access denied, so we have to make them
writeable before they can be removed.
$ "$TESTDIR/hghave" inotify || exit 80
$ hg init
$ echo "[extensions]" > .hg/hgrc
$ echo "inotify=" >> .hg/hgrc
$ hg inserve -d --pid-file .hg/inotify.pid
$ echo a > a
$ hg ci -Aqm0
$ hg co -q null
$ hg co -q
$ hg st
$ cat a
a
$ kill `cat .hg/inotify.pid`