message: refactor(utxo-lib): rename argument in hashForGoldSignature
  It is used as a boolean and the common name is `isSegwit`.
  Issue:
diff: @@ -798,7 +798,7 @@ Transaction.prototype.hashForCashSignature = function (inIndex, prevOutScript, i
  /**
  * Hash transaction for signing a specific input for Bitcoin Gold.
  */
  -Transaction.prototype.hashForGoldSignature = function (inIndex, prevOutScript, inAmount, hashType, sigVersion) {
  +Transaction.prototype.hashForGoldSignature = function (inIndex, prevOutScript, inAmount, hashType, isSegwit) {
  typeforce(types.tuple(types.UInt32, types.Buffer, /* types.UInt8 */ types.Number, types.maybe(types.UInt53)), arguments)
  // Bitcoin Gold also implements segregated witness
  @@ -812,7 +812,7 @@ Transaction.prototype.hashForGoldSignature = function (inIndex, prevOutScript, i
  }
  // BIP143 sighash activated in BitcoinCash via 0x40 bit
  - if (sigVersion || fUseForkId) {
  + if (isSegwit || fUseForkId) {
  if (types.Null(inAmount)) {
  throw new Error('Bitcoin Cash sighash requires value of input to be signed.')
  }
  