message: Fix formatting issues in thinblock.cpp for IsThinBlockValid()
  Also rather than check for size 0 used .empty()
diff: @@ -1104,7 +1104,7 @@ void SendXThinBlock(CBlock &block, CNode *pfrom, const CInv &inv)
  bool IsThinBlockValid(const CNode *pfrom, const std::vector<CTransaction> &vMissingTx, const CBlockHeader &header)
  {
  // Check that that there is at least one txn in the xthin and that the first txn is the coinbase
  - if(vMissingTx.size() <= 0)
  + if (vMissingTx.empty())
  {
  LogPrintf("No Transactions found in thinblock or xthinblock %s from peer %s (id=%d).\n",
  header.GetHash().ToString(), pfrom->addrName.c_str(), pfrom->id);
  