Add missing import socket for TCP*Pipe

scapy/scapypipes.py

@@ -3,6 +3,7 @@
 ## Copyright (C) Philippe Biondi <phil@secdev.org>
 ## This program is published under a GPLv2 license
 
+import socket
 from scapy.pipetool import Source,Drain,Sink
 from scapy.config import conf
 from scapy.utils import PcapReader, PcapWriter