message: fix: throw error if authType not set
diff: @@ -2,7 +2,7 @@ import { StacksTransaction } from './transaction';
  import { StacksPrivateKey, StacksPublicKey } from './keys';
  import { isSingleSig, nextVerification, SpendingConditionOpts } from './authorization';
  -import { cloneDeep } from './utils';
  +import { cloneDeep, txidFromData } from './utils';
  import { AuthType, PubKeyEncoding, StacksMessageType } from './constants';
  import { SigningError } from './errors';
  @@ -26,10 +26,14 @@ export class TransactionSigner {
  if (spendingCondition && !isSingleSig(spendingCondition)) {
  spendingCondition.fields.forEach(field => {
  if (field.contents.type === StacksMessageType.MessageSignature) {
  + if (!transaction.auth.authType) {
  + throw Error('"transaction.auth.authType" not defined');
  + }
  +
  const signature = field.contents;
  const nextVerify = nextVerification(
  this.sigHash,
  - transaction.auth.authType!,
  + transaction.auth.authType,
  spendingCondition!.fee,
  spendingCondition!.nonce,
  PubKeyEncoding.Compressed, // always compressed for multisig
  