Fixing BasicSetup link

The link points to BasicSetup link directs to https://github.com/ACRA/acra/blob/master/acra/wiki/BasicSetup (Page not found) instead of https://github.com/ACRA/acra/wiki/BasicSetup. Furthermore, URL in repository files should be absolute (not everybody reads it through GitHub)
Merge pull request #52 from pyricau/patch-1

Fixing BasicSetup link