CLEANUP: http: merge error handling for req* and http-request *

CLEANUP: http: merge error handling for req* and http-request *

The reqdeny/reqtarpit and http-request deny/tarpit were using
a copy-paste of the error handling code because originally the
req* actions used to maintain their own stats. This is not the
case anymore so we can use the same error blocks for both.

The http-request rulesets still has precedence over req* so no
functionality was changed.