[dnsdist] DoH: 302 redirecting / to a help page

[Stephane Bortzmeyer]

On Mon, Sep 16, 2019 at 11:13:03AM +0200,
 Remi Gacogne <remi.gacogne at powerdns.com> wrote 
 a message of 94 lines which said:

> supportpagemap = { newDOHResponseMapEntry("^/$", 302,
> "https://support.mydoman.com") }

It seems cool, but it fails for me:

Fatal Lua error: [string "chunk"]:9: attempt to call global 'newDOHResponseMapEntry' (a nil value)

% dnsdist --version
dnsdist 1.4.0-beta1 (Lua 5.1.4 [LuaJIT 2.0.5])
Enabled features: dns-over-tls(gnutls openssl) dns-over-https(DOH) ebpf fstrm ipcipher libsodium protobuf recvmmsg/sendmmsg systemd