Cannot configure NAT options from local placeshifter client.

So, with the likelyhood of more truly headless systems potentially emerging out there (unRAID/Linux), I'm seeing a bit of a shortcoming in the configurations options. The Configure Placeshifter Connection option isn't available to a local (same subnet) placeshifter client. Local miniclients from HDxxx and Android do show the option, but that leaves out the ability to configure my unRAID based server from my windows desktop (since Full Clients are also not able to do it).

The logic is:
`( IsServerUI() || (!IsDesktopUI() && IsRemoteUI()) || (IsLinuxOS() && GetServerProperty("linux/enable_nas",false)) ) && IsSageTVServerEnabled()
`
I'm not entirely sure on the fix - I don't know off hand if there is an API call to detect if a placeshifter is 'local' or not.