git-clone: stop dumb protocol from copying refs outside heads/ and tags/.

Most notably, the original code first copied refs/remotes/ that
remote side had to local, and overwrote them by mapping refs/heads/
from the remote when a dumb protocol transport was used.

This makes the clone behaviour by dumb protocol in line with the
git native and rsync transports.

Signed-off-by: Junio C Hamano <junkio@cox.net>

git-clone.sh

@@ -48,6 +48,10 @@ Perhaps git-update-server-info needs to be run there?"
 		case "$name" in
 		*^*)	continue;;
 		esac
+		case "$bare,$name" in
+		yes,* | ,heads/* | ,tags/*) ;;
+		*)	continue ;;
+		esac
 		if test -n "$use_separate_remote" &&
 		   branch_name=`expr "z$name" : 'zheads/\(.*\)'`
 		then