Revert breaking changes (#1202)

Author: lizhefeng

action/protocol/account/util/util.go

@@ -43,6 +43,7 @@ func LoadOrCreateAccount(sm protocol.StateManager, encodedAddr string, init *big
 	}
 	if errors.Cause(err) == state.ErrStateNotExist {
 		account.Balance = init
+		account.VotingWeight = big.NewInt(0)
 		if err := sm.PutState(addrHash, account); err != nil {
 			return nil, errors.Wrapf(err, "failed to put state for account %x", addrHash)
 		}

action/protocol/poll/protocol.go

@@ -460,6 +460,7 @@ func setCandidates(
 		if err != nil {
 			return errors.Wrapf(err, "failed to load or create the account for delegate %s", candidate.Address)
 		}
+		delegate.IsCandidate = true
 		if err := candidatesutil.LoadAndAddCandidates(sm, height, candidate.Address); err != nil {
 			return err
 		}