bitbake: server/process: Drop unused import

(Bitbake rev: 543315e6463f15ca7ab2b4ef3e8ed41bb4207ccf)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/server/process.py

@@ -20,7 +20,6 @@ import os
 import sys
 import time
 import select
-import signal
 import socket
 import subprocess
 import errno