Fix slow animal timeouts in 032_relfilenode_reuse.pl.

Fix slow animal timeouts in 032_relfilenode_reuse.pl.

Per BF animal chipmunk:  CREATE DATABASE could apparently fail due to an
AV process being in the template database and not quitting fast enough
for the 5 second timeout in CountOtherDBBackends().  The test script had
autovacuum_naptime=1s to encourage more activity and opening of fds, but
that wasn't strictly necessary for this test.  Take it out.

Per BF animal skink:  there was a 300s timeout for all tests in the
script, but apparently that was not enough under valgrind.  Let's use
the standard timeout $PostgreSQL::Test::Utils::timeout_default, but
restart it for each query we run.

Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/CA%2BhUKGKa8HNJaA24gqiiFoGy0ysndeVoJsHvX_q1-DVLFaGAmw%40mail.gmail.com