debug/macho: dropped monstrous URL from package comment

Relax. It's still in macho.go.

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/5653054

src/pkg/debug/macho/file.go

@@ -2,8 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Package macho implements access to Mach-O object files, as defined by
-// http://developer.apple.com/mac/library/documentation/DeveloperTools/Conceptual/MachORuntime/Reference/reference.html.
+// Package macho implements access to Mach-O object files.
 package macho
 
 // High level access to low level data structures.