message: Fix Mac Sigma build due to uninitialized value
diff: @@ -58,7 +58,7 @@ public:
  READWRITE(coinSerialNumber);
  READWRITE(version);
  - int64_t denomination_value;
  + int64_t denomination_value = 0;
  if (ser_action.ForRead()) {
  READWRITE(denomination_value);
  IntegerToDenomination(denomination_value, this->denomination);
  