zeroconf: flag third-party Zeroconf.py for ignore in check-code

hgext/zeroconf/Zeroconf.py

@@ -1571,3 +1571,5 b" if __name__ == '__main__':"
 	r.unregisterService(info)
 	print "   Unregister done."
 	r.close()
+
+# no-check-code