pgsql: doc: clarify that auth. names are lower case and case-sensitive

doc: clarify that auth. names are lower case and case-sensitive

This is true even for acronyms that are usually upper case, like LDAP.

Reported-by: Alvaro Herrera

Discussion: /messages/by-id/202205141521.2nodjabmsour@alvherre.pgsql

Backpatch-through: 10

Branch
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REL_14_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/21640e986518ab7d15b5a811cf2c5064af244249

Modified Files
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doc/src/sgml/client-auth.sgml | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)