htp_response: clear buffered data for body data
htp_response: clear buffered data for body data

There is a bug where the output buffer grows without bounds when we
treat the request line as response body data. Furthermore, the entire
buffer is passed to the response body data hooks with the _same_ data
many times.

OISF/libhtp,OISF/libhtp,OISF/libhtp,OISF/libhtp,OISF/libhtp,OISF/libhtp,OISF/libhtp