bitbake: bitbake-layers: add signal hander to avoid exception

Fixed:
bitbake-layers show-recipes | less
press "q" to exit

There will be a Broken pipe error output as follows:
"BrokenPipeError: [Errno 32] Broken pipe"

(Bitbake rev: 4fca9a07f2d6b0544977112672b786982d7bb8f2)

Signed-off-by: Zhixiong Chi <zhixiong.chi@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/bin/bitbake-layers

@@ -24,6 +24,7 @@ import logging
 import os
 import sys
 import argparse
+import signal
 
 bindir = os.path.dirname(__file__)
 topdir = os.path.dirname(bindir)
@@ -35,6 +36,7 @@ import bb.msg
 logger = bb.msg.logger_create('bitbake-layers', sys.stdout)
 
 def main():
+    signal.signal(signal.SIGPIPE, signal.SIG_DFL)
     parser = argparse.ArgumentParser(
         description="BitBake layers utility",
         epilog="Use %(prog)s <subcommand> --help to get help on a specific command",