Issue #27 - Do not create domain_keyset_idx if the keyset column does not exist

sql/ccreg.sql

@@ -254,7 +254,6 @@ CREATE TABLE Domain (
 CREATE INDEX domain_zone_idx ON Domain (Zone);
 CREATE INDEX domain_registrant_idx ON Domain (registrant);
 CREATE INDEX domain_nsset_idx ON Domain (nsset);
-CREATE INDEX domain_keyset_idx ON Domain (keyset);
 CREATE INDEX domain_exdate_idx ON domain (exdate);
 
 comment on table Domain is 'Evidence of domains';