slight optimization for dns_rbt_findnode() when bitstrings are involved: skip the hashing attempts entirely when not at the root of a level
slight optimization for dns_rbt_findnode() when bitstrings are involved:
skip the hashing attempts entirely when not at the root of a level

pecharmin/bind9,each/bind9-collab,each/bind9-collab,each/bind9-collab,pecharmin/bind9,each/bind9-collab,each/bind9-collab,pecharmin/bind9,each/bind9-collab,pecharmin/bind9,pecharmin/bind9,pecharmin/bind9