running "rules sync" without any parameters deletes all rules.

[simonc6372]

Hi,
If cortextool rules sync is ran without parameters for rule-files or rule-dirs then it assumes a null set of rules and deletes all the rules on the destination ruler without further warning.

I would expect if it was told to do a rules sync, then it should have either a rule-files, or a rule-dirs parameter and if one or other is not set, it should exit with an error. If deleting all rules is the desired behaviour, then this should happen with either parameter set to /dev/null

Thanks.