Improved tab completion for PostgreSQL parameters in enums

[bt21masumurak]

Hi

If you do tab completion in a situation like A, you will see ["on"] 
instead of [on].

A : "ALTER SYSTEM SET wal_compression TO "

I made a patch for this problem.

regards,
Kosei Masumuradiff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 4155d81252..86087e790b 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -969,7 +969,7 @@ Query_for_index_of_table \
 
 #define Query_for_enum \
 " SELECT name FROM ( "\
-"   SELECT pg_catalog.quote_ident(pg_catalog.unnest(enumvals)) AS name "\
+"   SELECT pg_catalog.unnest(enumvals) AS name "\
 "     FROM pg_catalog.pg_settings "\
 "    WHERE pg_catalog.lower(name)=pg_catalog.lower('%s') "\
 "    UNION ALL " \