message: Add extra help text to importprivkey
  Reduce the confusion around importing when rescan is off. Add text
  to note that you must you a label if you do not want to rescan.
diff: @@ -101,9 +101,10 @@ UniValue importprivkey(const UniValue &params, bool fHelp)
  "\nExamples:\n"
  "\nDump a private key\n" +
  HelpExampleCli("dumpprivkey", "\"myaddress\"") + "\nImport the private key with rescan\n" +
  - HelpExampleCli("importprivkey", "\"mykey\"") + "\nImport using a label and without rescan\n" +
  - HelpExampleCli("importprivkey", "\"mykey\" \"testing\" false") + "\nAs a JSON-RPC call\n" +
  - HelpExampleRpc("importprivkey", "\"mykey\", \"testing\", false"));
  + HelpExampleCli("importprivkey", "\"mykey\"") + "\nImport using rescan and label\n" +
  + HelpExampleCli("importprivkey", "\"mykey\" \"mylabel\"") + "\nImport without rescan (must use a label)\n" +
  + HelpExampleCli("importprivkey", "\"mykey\" \"mylabel\" false") + "\nAs a JSON-RPC call\n" +
  + HelpExampleRpc("importprivkey", "\"mykey\", \"mylabel\", false"));
  LOCK2(cs_main, pwalletMain->cs_wallet);
  