revert patch that breaks build.

commit 7f5ff26f
Author: Travis Cross <tc@traviscross.com>
Date:   Wed Nov 2 18:04:26 2011 +0000

    remove libs/ldns/install-sh as it's being auto-generated

libs/.gitignore

@@ -887,6 +887,7 @@ missing
 !/ldns/drill/install-sh
 !/ldns/examples/config.h.in
 !/ldns/examples/configure
+!/ldns/install-sh
 !/ldns/ldns/config.h.in
 !/libdingaling/config.guess
 !/libdingaling/config.sub