Fix tests for Postgres 9.3

Postgres 9.3 turns messages about implicit indexes and sequences from NOTICE
to DEBUG1 so the tests fail with a default 9.3 server configuration because
the client doesn't get any NOTICE. Fix it by using another query that
generates a NOTICE on all versions between 7.4 and 9.3, namely asking for
reindexing of a table that has no defined index.