The test case for this doesn't trigger, but the failing VCL (when
given in a file with -f) looks like:

director squid round-robin {
	 { .backend = { .host = "127.0.0.1"; .port = "3131"; } }
}

director dnsdir dns {
	 .list = {
	       "201.7.184.0"/32;
	 }
}

sub vcl_recv {
    set req.backend = dnsdir;
}

Fixes #1295