message: [RPC]: Don't allow backupwallet to overwrite the wallet-in-use
  Prevent file access collisions and possible file corruption by refusing
  to overwrite the current wallet in use.
diff: @@ -1019,6 +1019,10 @@ bool AttemptBackupWallet(const CWallet& wallet, const filesystem::path& pathSrc,
  bool retStatus;
  string strMessage;
  try {
  + if (boost::filesystem::equivalent(pathSrc, pathDest)) {
  + LogPrintf("cannot backup to wallet source file %s\n", pathDest.string());
  + return false;
  + }
  #if BOOST_VERSION >= 105800 /* BOOST_LIB_VERSION 1_58 */
  filesystem::copy_file(pathSrc.c_str(), pathDest, filesystem::copy_option::overwrite_if_exists);
  #else
  