BUG/MEDIUM: filters: Don't call TCP callbacks for HTX streams

BUG/MEDIUM: filters: Don't call TCP callbacks for HTX streams

For now, TCP callbacks are incompatible with the HTX streams because they are
designed to manipulate raw buffers. A new callback will probably be added to be
used in both modes, raw and HTX. So, for HTX streams, these callbacks are
ignored. This should not be a real problem because there is no known filters,
expect the trace filter, implementing these callbacks.

This patch must be backported to 2.0 and 1.9.