.gitignore: try again with the sorting thing
.gitignore: try again with the sorting thing

I have no idea how this got messed up in the first place, but it's
obviously wrong, so let's fix it.

cockpit-project/cockpit,martinpitt/cockpit,martinpitt/cockpit,martinpitt/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,martinpitt/cockpit,martinpitt/cockpit,cockpit-project/cockpit,mvollmer/cockpit,mvollmer/cockpit,mvollmer/cockpit,cockpit-project/cockpit,mvollmer/cockpit,mvollmer/cockpit