Revert "Correct this test for good"

This reverts commit a4e07fc5.

It still fails on FreeBSD and SunOS.

bin/varnishtest/tests/c00003.vtc

 varnishtest "Check that we fail to start with erroneous -a/-b arguments"
 
 # Duplicate -a arguments
-shell -err -expect "have same address" {
-	varnishd -d -a 127.0.0.1:${random_port} \
-		-a 127.0.0.1:${random_port} -b localhost:80
+# XXX: this cannot be tested reliably, we tolerate port collision
+shell -err -match "have same address|already in use" {
+	varnishd -d -a 127.0.0.1:38484 -a 127.0.0.1:38484 -b localhost:80
 }
 
 # -a bad protocol specs

bin/varnishtest/vtc_main.c

@@ -499,9 +499,6 @@ ip_magic(void)
 	/* Expose a backend that is forever down. */
 	extmacro_def("bad_backend", "%s %s", abuf, pbuf);
 
-	/* Expose a port that ought to be free */
-	extmacro_def("random_port", "%s", pbuf);
-
 	/*
 	 * We need an IP number which will not repond, ever, and that is a
 	 * lot harder than it sounds.  This IP# is from RFC5737 and a