[DHCP Client] XID is always initialized with 0xABCD0001 instead of random value

The DHCP/BootP XID is initialized with the value 0xABCD0001, but according to RFC2131 Section 4.1 it should always be randomly generated:

The 'xid' field is used by the client to match incoming DHCP messages
with pending requests.  A DHCP client MUST choose 'xid's in such a
way as to minimize the chance of using an 'xid' identical to one used
by another client. For example, a client may choose a different,
random initial 'xid' each time the client is rebooted, and
subsequently use sequential 'xid's until the next reboot.  Selecting
a new 'xid' for each retransmission is an implementation decision.  A
client may choose to reuse the same 'xid' or select a new 'xid' for
each retransmitted message.