Fix failing test for missing indexes handling
Fix failing test for missing indexes handling

There's a supersearch test that verifies that supersearch works if there
are missing indexes--it should return errors. The test originally
required there to be 3 errors, but for some reason it doesn't work today
(2021-01-04). I poked at it a bit and then decided to change the test
because we don't care how many missing indexes there are--just that
there are missing indexes and supersearch works.

lonnen/socorro,lonnen/socorro,lonnen/socorro,lonnen/socorro