macos屏蔽更新

## Mac Software Update (sysin)
127.0.0.1 swdist.apple.com
127.0.0.1 swscan.apple.com
127.0.0.1 swcdn.apple.com  #optional, download url
127.0.0.1 gdmf.apple.com
127.0.0.1 mesu.apple.com
127.0.0.1 xp.apple.com