fix: change config param name from startUdfd to udf

tests/script/tsim/query/udf.sim

@@ -3,7 +3,7 @@ system sh/stop_dnodes.sh
 system sh/deploy.sh -n dnode1 -i 1
 system sh/cfg.sh -n dnode1 -c wallevel -v 2
 system sh/cfg.sh -n dnode1 -c numOfMnodes -v 1
-system sh/cfg.sh -n dnode1 -c startUdfd -v 1
+system sh/cfg.sh -n dnode1 -c udf -v 1
 
 print ========= start dnode1 as LEADER
 system sh/exec.sh -n dnode1 -s start