tests: replace `cd ..` with an absolute path in a couple ssh tests These tests are broken under py3 on Windows to the point where the `cd ..` was actually escaping into the system wide $TEMP. The subsequent `hg init` created a repo there, and then added a local extension to the hgrc. This breaks every single subsequent test when it tries to `hg init` in its $TESTTMP, and can't load the localwrite.py extension. And since I botched this the first time and replaced the wrong `cd ..`, this just replaces all of them. I've noticed test garbage in $TEMP recently, and maybe this will help. Perhaps `hg init` shouldn't load the config for the local repo, but this is an easy enough workaround for now.