Remove SO_BSDCOMPAT usage, it's ignore since Linux 2.4

Remove SO_BSDCOMPAT usage, it's ignore since Linux 2.4

The SO_BSDCOMPAT socket option is no-op since Linux 2.4, see the manpage:

SO_BSDCOMPAT
	Enable BSD bug-to-bug compatibility.  This is used by the UDP protocol
	module in Linux 2.0 and 2.2.  If enabled, ICMP errors received for a UDP
	socket will not be passed to the user program.  In later kernel
	versions, support for this option has been phased out: Linux 2.4
	silently ignores it, and Linux 2.6 generates a kernel warning (printk())
	if a program uses this option.  Linux 2.0 also enabled BSD bug-to-bug
	compatibility options (random header changing, skipping of the broadcast
	flag) for raw sockets with this option, but that was removed in Linux
	2.2.