revert the test change that fais on 32-bit

Closes #3228

mysql-test/main/long_unique_bugs.result

@@ -59,8 +59,8 @@ update t1 set f = 'foo';
 select * from t1;
 pk	f
 1	foo
-select pk, f, row_end > DATE'2106-01-01' from t1 for system_time all;
-pk	f	row_end > DATE'2106-01-01'
+select pk, f, row_end > DATE'2030-01-01' from t1 for system_time all;
+pk	f	row_end > DATE'2030-01-01'
 1	foo	1
 1	foo	0
 1	bar	0

mysql-test/main/long_unique_bugs.test

@@ -59,7 +59,7 @@ update t1 set f = 'bar';
 select * from t1;
 update t1 set f = 'foo';
 select * from t1;
-select pk, f, row_end > DATE'2106-01-01' from t1 for system_time all;
+select pk, f, row_end > DATE'2030-01-01' from t1 for system_time all;
 drop table t1;
 
 --echo #