Update expected output of new test

Forgot to 'git add' the file after tweaking the test as submitted :-(

Per buildfarm

src/test/regress/expected/insert_conflict.out

@@ -884,9 +884,13 @@ insert into parted_conflict values (40, 'forty');
 insert into parted_conflict_1 values (40, 'cuarenta')
   on conflict (a) do update set b = excluded.b;
 ERROR:  there is no unique or exclusion constraint matching the ON CONFLICT specification
+drop table parted_conflict;
 -- test whole-row Vars in ON CONFLICT expressions
+create table parted_conflict (a int, b text, c int) partition by range (a);
+create table parted_conflict_1 (drp text, c int, a int, b text);
+alter table parted_conflict_1 drop column drp;
 create unique index on parted_conflict (a, b);
-alter table parted_conflict add c int;
+alter table parted_conflict attach partition parted_conflict_1 for values from (0) to (1000);
 truncate parted_conflict;
 insert into parted_conflict values (50, 'cincuenta', 1);
 insert into parted_conflict values (50, 'cincuenta', 2)