remove autogenerated file libs/ldns/install-sh

Re-bootstrapping is needed after this change.  Previously CentOS 5
systems wouldn't build correctly without this file in tree, but we've
adjusted bootstrap to compensate.

bootstrap.sh

@@ -389,18 +389,19 @@ bootstrap_fs() {
 
 bootstrap_libs_pre() {
   case "$1" in
-    ldns)
-      # This file shouldn't even be in the tree as it's autogenerated
-      # during bootstrap, but some people report it breaks the build
-      # if it's not there.  Let's prevent it from getting accidentally
-      # updated.
-      (cd $BASEDIR/libs/ldns && cp -a install-sh install-sh~) ;;
+    *) return 0;;
   esac
 }
 
 bootstrap_libs_post() {
   case "$1" in
-    ldns) (cd $BASEDIR/libs/ldns && mv install-sh~ install-sh) ;;
+    ldns)
+      cd $BASEDIR/libs/ldns
+      if test ! -x install-sh; then
+        ex automake --add-missing --copy
+        ex rm -rf autom4te*.cache
+      fi
+      ;;
   esac
 }