mod_http_oauth2: Stricten check of urlencoded form data
Because type(formdecode("string without equals sign")) == "string", so
best avoid continuing in that case, even if strings mostly behave as
tables as long as you don't hit one of the __index methods.
Introduction
============
This module checks the IP address of newly registered users against a
DNS block list. If a positive match is found, it gets logged.
Configuration
=============
Option Type Default
------------------- -------- ------------
registration\_rbl string *Required*