Retire git-fetch-dumb-http and missing-revs

Now git-http-pull knows how to do packed repo, retire scripted
hacks I placed as a stop-gap measure.

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

git-fetch-script

@@ -20,22 +20,8 @@ http://* | https://*)
 		echo >&2 "Failed to fetch $merge_head from $merge_repo"
 	        exit 1
 	}
-	git-fetch-dumb-http "$head" "$@"
-	case "$?" in
-	0) ;;
-	2) no_dumb_http_support=1 ;;
-	*) exit;;
-	esac
 	echo Fetching "$merge_head" using http
-	git-http-pull -v -a "$head" "$merge_repo/" || {
-	    case "$no_dumb_http_support" in
-	    1)
-		echo >&2 "* This could be because the $merge_repo is packed without"
-		echo >&2 "  preparing dumb server support files."
-		;;
-	    esac
-	    exit 1
-	}
+	git-http-pull -v -a "$head" "$merge_repo/" || exit
 	;;
 rsync://*)
 	rsync -L "$merge_repo/$merge_head" "$TMP_HEAD" || exit 1