Fix for drop db message format changes

Author: tatsuo-ishii

src/test/regress/expected/euc_jp.out

@@ -1,5 +1,5 @@
 drop table �׻����Ѹ�;
-ERROR:  Relation '�׻����Ѹ�' does not exist
+ERROR:  table "�׻����Ѹ�" is nonexistent
 create table �׻����Ѹ� (�Ѹ� text, ʬ�ॳ���� varchar, ����1A���� char(16));
 create index �׻����Ѹ�index1 on �׻����Ѹ� using btree (�Ѹ�);
 create index �׻����Ѹ�index2 on �׻����Ѹ� using hash (ʬ�ॳ����);