Fix profiles not updating (William Casarin)
profiles: switch to pubkeys for last fetched time (William Casarin)
db: add ndb_read_last_profile_fetch (William Casarin)
pushed to nostrdb:refs/heads/master
http://git.jb55.com/nostrdb/commit/9ce284a2f6d91bd1ae3786aec9010559a0986965.html