Removing expired keys

[Robert J. Hansen]

> Didn't look very hard, did you?  :)

Before anyone accuses me of being less than helpful: Jerry asked this
same question two years ago, got an answer on-list, verified that it
solved his problem, and then just now asked the same question, got an
answer from the same person, and was referred to the earlier thread.  A
touch of mild ribbing seems to be in order.  :)