remove outdated tesla subnet from dhcpd

current dhcpd conf still listed this

subnet 208.80.153.192 netmask 255.255.255.192
..
option domain-name "tesla.wikimedia.org";

see the "tesla" in there, that's pre-labs stuff,

this came up when searching for remnants of old "tesla"
things (RT #3801)

Change-Id: I8dcf9ee5ffff4679da1a0430b78d02f2079a8100
Merge "remove outdated tesla subnet from dhcpd" into production