pgsql: Fix expected output of xml_2.out

Fix expected output of xml_2.out

Per buildfarm members snakefly, parula and prion, that reflect the
results coming from the latest versions of libxml2.

Oversight in b8da37b in the shape of an incorrect copy-paste.  The CI
was green, but it does not stress this expected output.

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/737668d9e320e452b4eeec6e5cec86284de67e0f

Modified Files
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src/test/regress/expected/xml_2.out | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)