Shave some cycles off subscription/t/100_bugs.pl tests.

Shave some cycles off subscription/t/100_bugs.pl tests.

We can re-use the clusters set up for this test script's first test,
instead of generating new ones.  On my machine this is good for
about a 20% reduction in this script's runtime, from ~6.5 sec to
~5.2 sec.

This idea could be taken further, but it'd require a much more invasive
patch.  These cases are easy because the Perl variable names were
already being re-used.

Anton A. Melnikov

Discussion: https://postgr.es/m/eb7aa992-c2d7-6ce7-4942-0c784231a362@inbox.ru