Fix: allow backups to continue when some destinations fail instead of failing completely

[imhayatunnabi]

An improvement is necessary to allow backups to continue when some destinations fail instead of failing completely. For example, if we have backups going to both local and S3, and S3 is down, the backup can still succeed by saving to local storage only

When trying to use the continue_on_failure configuration option, the application crashes with "Unknown named parameter $continueOnFailure" error. This happens because the DestinationConfig constructor is missing the parameter that the fromArray() method tries to pass to it.