Small error message improvement

src/backend/commands/tablecmds.c

@@ -16673,7 +16673,7 @@ AttachPartitionEnsureIndexes(Relation rel, Relation attachrel)
 						 errmsg("cannot attach foreign table \"%s\" as partition of partitioned table \"%s\"",
 								RelationGetRelationName(attachrel),
 								RelationGetRelationName(rel)),
-						 errdetail("Table \"%s\" contains unique indexes.",
+						 errdetail("Partitioned table \"%s\" contains unique indexes.",
 								   RelationGetRelationName(rel))));
 			index_close(idxRel, AccessShareLock);
 		}

src/test/regress/expected/foreign_data.out

@@ -773,7 +773,7 @@ CREATE FOREIGN TABLE ft_part2 (a INT NOT NULL) SERVER s0;
 ALTER TABLE lt1 ATTACH PARTITION ft_part2
   FOR VALUES FROM (1000) TO (2000);                             -- ERROR
 ERROR:  cannot attach foreign table "ft_part2" as partition of partitioned table "lt1"
-DETAIL:  Table "lt1" contains unique indexes.
+DETAIL:  Partitioned table "lt1" contains unique indexes.
 DROP TABLE lt1;
 DROP FOREIGN TABLE ft_part2;
 CREATE TABLE lt1 (a INT) PARTITION BY RANGE (a);
@@ -801,7 +801,7 @@ DETAIL:  Table "lt1_part1" contains indexes that are unique.
 CREATE FOREIGN TABLE ft_part_1_2 (a INT NOT NULL) SERVER s0;
 ALTER TABLE lt1_part1 ATTACH PARTITION ft_part_1_2 FOR VALUES FROM (100) TO (200);
 ERROR:  cannot attach foreign table "ft_part_1_2" as partition of partitioned table "lt1_part1"
-DETAIL:  Table "lt1_part1" contains unique indexes.
+DETAIL:  Partitioned table "lt1_part1" contains unique indexes.
 DROP TABLE lt1;
 DROP FOREIGN TABLE ft_part_1_2;
 -- ALTER FOREIGN TABLE