bug: BootNotificationConfirmation does not accept interval=0

[thetric]

According to the OCPP 1.6 spec it should be allowed to specify interval=0:

"If that interval value is zero, the Charge Point chooses a waiting interval on its own, in a way that avoids flooding the Central System with requests."

--- Source: OCPP 1.6 spec, section 4.2. Boot Notification

[TVolden]

Hi @thetric,

Thanks for your input. As far as I can see the validation is the cause of the problem:

Java-OCA-OCPP/ocpp-v1_6/src/main/java/eu/chargetime/ocpp/model/core/BootNotificationConfirmation.java

Line 165 in 29d21f7

valid &= interval != null && interval > 0;

I'll make a fix.