pgsql: doc: Remove stray comma from list of psql options

doc: Remove stray comma from list of psql options

Back in 7.2 the list of options had short options and long options
on the same line separated by comma, but since 7.3 they are listed
separate lines. The comma on -X was left behind so fix by removing
and backpatching all the way.

Reported-by: y.saburov@gmail.com
Discussion: https://postgr.es/m/171267154345.684.7212826057932148541@wrigleys.postgresql.org
Backpatch-through: v12

Branch
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REL_16_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/db4a0280d3671f0f88836e4f6987e333303fc771

Modified Files
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doc/src/sgml/ref/psql-ref.sgml | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)