fix action precedence

“Search For…” was being outranked by “Open URL” because an older key
was being used.

This bit me on a fresh install under 10.10 and has bitten [at least one user][1].

[1]: /quicksilver/Quicksilver/commit/2aba72904ece9d5c56a7825a4b644cedcb6948cb#commitcomment-6453509