pgsql: Fix range for commit_siblings in sample conf

Fix range for commit_siblings in sample conf

The range for commit_siblings was incorrectly listed as starting on 1
instead of 0 in the sample configuration file.  Backpatch down to all
supported branches.

Author: Man Zeng <zengman@halodbtech.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/tencent_53B70BA72303AE9C6889E78E@qq.com
Backpatch-through: 14

Branch
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REL_17_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/1aa5a029fcef7f4f971f3a2b686d2d4280ee44c2

Modified Files
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src/backend/utils/misc/postgresql.conf.sample | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)