message: fix sum_type and serialise pubk in cbor before serialising in cbor
diff: @@ -259,7 +259,7 @@ impl AddrType {
  }
  impl ToCBOR for AddrType {
  fn encode(&self, buf: &mut Vec<u8>) {
  - hs_cbor::sumtype_start(self.to_byte(), 0, buf);
  + cbor::cbor_uint_small(self.to_byte(), buf);
  }
  }
  @@ -414,7 +414,9 @@ impl ToCBOR for SpendingData {
  match self {
  &SpendingData::PubKeyASD(ref xpub) => {
  hs_cbor::sumtype_start(0, 1, buf);
  - hs_cbor_util::cbor_xpub(&xpub, buf);
  + let mut vec = vec![];
  + hs_cbor_util::cbor_xpub(xpub, &mut vec);
  + cbor::cbor_bs(&vec, buf);
  }
  &SpendingData::ScriptASD(ref _script) => {
  panic!();
  