Fixed the automatic wiki documentation update

After lessons learned from https://github.com/OpenRA/OpenRAWeb/pull/135 I resolved by https://github.com/OpenRA/OpenRA/issues/5900 by git cloning into `$HOME` to avoid the git inside an existing git repository problem. When testing locally I suggest to remove the lines

```
git config --global user.email "travis@travis-ci.org"
git config --global user.name "travis-ci"
```