add some trace for 'check_bp_account'

contracts/hddpool/hddpool.cpp

@@ -871,6 +871,7 @@ bool hddpool::is_bp_account(uint64_t uservalue)
 void hddpool::check_bp_account(account_name bpacc, uint64_t id, bool isCheckId) {
     account_name shadow;
     uint64_t seq_num = eosiosystem::getProducerSeq(bpacc, shadow);
+    print("bpname ----", name{bpacc}, "\n");
     eosio_assert(seq_num > 0 && seq_num < 22, "invalidate bp account");
     if(isCheckId) {
       eosio_assert( (id%21) == (seq_num-1), "can not access this id");