Remove /o flag from iterate_hash_list()

* /o in the -next and -last regexes causes the regex pattern
  to freeze with whatever prefix happens to be used on the first
  run of the routine. This is particularly pernicious in pre-fork
  where the daemon may be used dozens of times after the initial
  run that freezes the pattern.

* Modified flags to match those of the regex counterparts in
  iterate_array_list().