message: Convert number always into big endian hex string
  EVM read hex numbers in big endian representation
diff: #include <serialize.h>
  #include <util/strencodings.h>
  #include <regex>
  -#include <iomanip>
  #include <stdarg.h>
  @@ -1249,17 +1248,15 @@ int ScheduleBatchPriority()
  }
  std::string toHexString(int64_t intValue) {
  + //Store big endian representation in a vector
  + uint64_t num = (uint64_t)intValue;
  + std::vector<unsigned char> bigEndian;
  + for(int i=sizeof(num) -1; i>=0; i--){
  + bigEndian.push_back( (num>>(8*i)) & 0xff );
  + }
  - std::string hexStr;
  -
  - // Integer value to hex string
  - std::stringstream sstream;
  - sstream << "0x" << std::setfill ('0') << std::setw(2) << std::hex << (int64_t)intValue;
  -
  - hexStr= sstream.str();
  - sstream.clear();
  -
  - return hexStr;
  + //Convert the vector into hex string
  + return "0x" + HexStr(bigEndian.begin(), bigEndian.end());
  }
  void ReplaceInt(const int64_t& number, const std::string& key, std::string& str)
  