WSGI: Use select.poll instead of select.select .

Avoids the infamous 1024 file descriptor limit. No functional change
expected, as it seems unlikely this bug ever triggered on waitress-managed
file descriptors.

product/ERP5/bin/zopewsgi.py

@@ -178,4 +178,5 @@ def runwsgi():
         listen=args.address,
         logger=logging.getLogger("access"),
         threads=conf.zserver_threads,
+        asyncore_use_poll=True,
     ).run()