Fedora 25 FEDORA-2017-fff6e1af37 Moderate Fedmsg Validation Issues

Python API used around Fedora Infrastructure to send and receive messages with

zeromq. Includes some CLI tools.

Fix validation logic in the base consumer The base consumer is intended to only derive its validation switch from the on-disk configuration if the child class doesn't override the validate_signatures switch. There was a bug here where the default value provided in the base class made it appear as if *all* child consumers had turned *off* validation, which is incorrect. This fix turns on signature validation by default while preserving the ability of child consumersto override the on-disk configuration in special cases. - Fixes: CVE-2017-1000001 - Reviewed-by: Patrick Uiterwijk