b80aa36946
rndc_config_file and rndc_key_file are not required in every deployment because designate override the minimum options such as host or port when running the rndc command. Drop the hard-coded default so that users don't have to create these files although one/both of these are unused. Change-Id: Ibb1caf04b1a911b1a83c625c61510631d9c672da