REGTEST: Add option to use HTX prefixed by the macro 'no-htx'

So some tests have been removed.
diff --git a/reg-tests/ssl/b00000.vtc b/reg-tests/ssl/b00000.vtc
index d1b48fb..30030e3 100644
--- a/reg-tests/ssl/b00000.vtc
+++ b/reg-tests/ssl/b00000.vtc
@@ -27,6 +27,7 @@
 
   listen frt
     mode http
+    ${no-htx} option http-use-htx
     bind "fd@${frt}" ssl crt ${testdir}/common.pem
     http-request redirect location /
 } -start