MINOR: http-rules: Update txn flags and status when a deny rule is executed

MINOR: http-rules: Update txn flags and status when a deny rule is executed

When a deny rule is executed, the flag TX_CLDENY and the status code are set on
the HTTP transaction. Now, these steps are handled by the code executing the
deny rule. So into http_req_get_intercept_rule() for the request and
http_res_get_intercept_rule() for the response.