Bye bye, kern.emul.freebsd

Pointed out by aja@

src/etc/etc.i386/sysctl.conf

@@ -5,6 +5,5 @@
 #machdep.userldt=1		# allow userland programs to play with ldt,
 				# required by some ports
 #kern.emul.aout=1		# enable running dynamic OpenBSD a.out bins
-#kern.emul.freebsd=1		# enable running FreeBSD binaries
 #kern.emul.linux=1		# enable running Linux binaries
 #kern.emul.svr4=1		# enable running SVR4 binaries