message: Distinctive error message if private alert key is not in right format.
diff: @@ -268,7 +268,9 @@ Value sendalert(const Array& params, bool fHelp)
  alert.vchMsg = vector<unsigned char>(sMsg.begin(), sMsg.end());
  vector<unsigned char> vchPrivKey = ParseHex(params[1].get_str());
  - key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end()), false); // if key is not correct openssl may crash
  + if (!key.SetPrivKey(CPrivKey(vchPrivKey.begin(), vchPrivKey.end()), false)) // if key is not correct openssl may crash
  + throw runtime_error(
  + "Private key is in wrong format!\n");
  if (!key.Sign(Hash(alert.vchMsg.begin(), alert.vchMsg.end()), alert.vchSig))
  throw runtime_error(
  "Unable to sign alert, check private key?\n");
  