Set AMQP_SPEC default to None to fix a KeyError exception
Set AMQP_SPEC default to None to fix a KeyError exception

If the configuration file does not provide a value (and most users
do not know what value to provide), it's ok to leave it as None as
the underlying AMQP listener code will pick a sensible default

deniszh/carbon,graphite-project/carbon,mleinart/carbon,johnseekins/carbon,obfuscurity/carbon,criteo-forks/carbon,mleinart/carbon,graphite-project/carbon,pu239ppy/carbon,deniszh/carbon,piotr1212/carbon,obfuscurity/carbon,iain-buclaw-sociomantic/carbon,criteo-forks/carbon,krux/carbon,krux/carbon,pu239ppy/carbon,piotr1212/carbon,iain-buclaw-sociomantic/carbon,johnseekins/carbon