Adding new http converter: rfc7239_is_valid.
Takes a string representing 7239 forwarded header single value as
input and returns bool:TRUE if header is RFC compliant and
bool:FALSE otherwise.
Example:
acl valid req.hdr(forwarded),rfc7239_is_valid
#input: "for=127.0.0.1;proto=http"
# output: TRUE
#input: "proto=custom"
# output: FALSE
Depends on:
- "MINOR: http_ext: introduce http ext converters"