The buildfarm members using -DCLOBBER_CACHE_ALWAYS still don't like this
test.  Some experimentation shows that on my machine, isolationtester's
query to check for "waiting" state takes 2 to 2.5 seconds to bind+execute
under -DCLOBBER_CACHE_ALWAYS.  Set the timeouts to 5 seconds to leave some
headroom for possibly-slower buildfarm critters.

Really we ought to fix the "waiting" query, which is not only horridly
slow but outright wrong in detail; and then maybe we can back off these
timeouts.  But right now I'm just trying to get the buildfarm green again.