pgsql: Stabilize 039_end_of_wal test.

Stabilize 039_end_of_wal test.

The first test was sensitive to the insert LSN after setting up the
catalogs, which depended on environmental things like the locales on the
OS and usernames. Switch to a new WAL file before the first test, as a
simple way to put every computer into the same state.

Back-patch to all supported releases.

Reported-by: Anton Voloshin <a(dot)voloshin(at)postgrespro(dot)ru>
Reported-by: Nathan Bossart <nathandbossart(at)gmail(dot)com>
Reviewed-by: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Reviewed-by: Nathan Bossart <nathandbossart(at)gmail(dot)com>
Discussion: https://postgr.es/m/b26aeac2-cb6d-4633-a7ea-945baae83dcf%40postgrespro.ru

Branch
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REL_15_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/777f50b9b5822d1058c59fc2ee1d1a7e9c766bf8

Modified Files
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src/test/recovery/t/039_end_of_wal.pl | 6 ++++++
1 file changed, 6 insertions(+)