fix case issue

tests/script/tsim/stable/column_drop.sim

@@ -129,7 +129,8 @@ endi
 
 print ========== step2 drop column c5
 sql alter table db.stb drop column c5
-sql insert into db.ctb values(now+2s, 1, 2, 3, 4, 5)
+sql_error insert into db.ctb values(now+2s, 1, 2, 3, 4, 5)
+sql insert into db.ctb values(now+2s, 1, 2, 3, 4)
 sql insert into db.ctb values(now+3s, 1, 2, 3, 4)
 sql_error insert into db.ctb values(now+2s, 1, 2, 3, 4, 5)
 
@@ -206,4 +207,4 @@ if $data[7][0] != t3 then
   return -1
 endi
 
-system sh/exec.sh -n dnode1 -s stop -x SIGINT
\ No newline at end of file
+system sh/exec.sh -n dnode1 -s stop -x SIGINT