[TD-225] remove the invalid test case.

tests/script/general/parser/projection_limit_offset.sim

@@ -317,7 +317,6 @@ sql_error select count(*) from group_tb0 where ts in ('2016-1-1 12:12:12');
 sql_error select count(*) from group_tb0 where ts < '12:12:12';
 
 #===============================sql for twa==========================================
-sql_error select twa(c1) from group_tb0;
 sql_error select twa(c1) from group_stb0;
 sql_error select twa(c2) from group_stb0 where ts<now and ts>now-1h group by t1;
 sql_error select twa(c2) from group_stb0 where ts<now and ts>now-1h group by tbname,t1;