update systemd to a version including LLMNR so Windows boxes won't need Bonjour

[jbrzusto]

systemd-resolved includes an LLMNR responder as of some version in mid-2015.
So to permit use of sgpi.local or SG-ABCDXXXXYYYY.local to work in browser URLs from
windows clients, we need to update.

• alternatively, run a specific llmnr responder such as https://github.com/tklauser/llmnrd
• figure out what name to use on the llmnr responder so that 'sgpi.local' works on the client.
  Is it sgpi or sgpi.local?