message: add block signature
diff: @@ -118,6 +118,7 @@ class TestHeaderAndShortIDs {
  public:
  CBlockHeader header;
  uint64_t nonce;
  + std::vector<unsigned char> vchBlockSig;
  std::vector<uint64_t> shorttxids;
  std::vector<PrefilledTransaction> prefilledtxn;
  @@ -143,6 +144,7 @@ public:
  inline void SerializationOp(Stream& s, Operation ser_action) {
  READWRITE(header);
  READWRITE(nonce);
  + READWRITE(vchBlockSig);
  size_t shorttxids_size = shorttxids.size();
  READWRITE(VARINT(shorttxids_size));
  shorttxids.resize(shorttxids_size);
  