pgsql: Fix build of documentation - Mailing list pgsql-committers

Fix build of documentation

Oversight in 1c42346, which has incorrectly shaped a <xref> markup.
Only v10 and v9.6 got broken.

Reported-by: Stefan Kaltenbrunner
Discussion: https://postgr.es/m/675cde90-a8dc-faeb-4701-d35a89ee06a2@kaltenbrunner.cc

Branch
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REL_10_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/ba7359d5fed01ec20560fba98f57a67b041614b9

Modified Files
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doc/src/sgml/ref/pg_receivewal.sgml | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)