Allow using dump_dns on the read-only broker
Allow using dump_dns on the read-only broker

The command class missed the required annotation.

Reviewed-By: Wesley Hertlein <ca32100e9f664971b15d1470ddc7f009d907efd3@morganstanley.com>

quattor/aquilon,guillaume-philippon/aquilon,quattor/aquilon,stdweird/aquilon,stdweird/aquilon,stdweird/aquilon,quattor/aquilon,guillaume-philippon/aquilon,guillaume-philippon/aquilon