According to RFC 2132 (9.14. Client identifier) a hardware type of 0

According to RFC 2132 (9.14. Client identifier) a hardware type of 0
should be used when the client identifier is not a hardware address,
for example if it's just a string. It turns out that the majority of
dhcp clients (and possibly servers?) does not do this but rather
transmits the client identifier verbatim if a string is
configured. The first character becomes the hardware type.
Make dhcpleased(8) behave the same.
Difference in behavior with dhclient(8) and interoperability issues
with dhcp(8) first pointed out by Olivier Cherrier on misc@
OK sthen
fine to get it in for 7.0 deraadt