stream: fix SYN_SENT RST/FIN injection

RST injection during the SYN_SENT state could trick Suricata into marking
a session as CLOSED. The way this was done is: using invalid TSECR value
in RST+ACK packet. The ACK was needed to force Linux into considering the
TSECR value and compare it to the TSVAL from the SYN packet.

The second works only against Windows. The client would not use a TSVAL
but the RST packet would. Windows will reject this, but Suricata considered
the RST valid and triggered the CLOSED logic.

This patch addresses both. When the SYN packet used timestamp support
the timestamp of incoming packet is validated. Otherwise, packet responding
should not have a timestamp.

Bug #3286

Reported-by: Nicolas Adba