message: Update help comments for getstat
  Include a comment on how to get a list of statistic names that
  can be used in the getstat commmand.
diff: @@ -1400,7 +1400,7 @@ UniValue getstat(const UniValue &params, bool fHelp)
  if (fHelp || (params.size() < 1))
  throw runtime_error("getstat"
  "\nReturns the current settings for the network send and receive bandwidth and burst in "
  - "kilobytes per second.\n"
  + "kilobytes per second.\nTo get a list of available statistics use \"getstatlist\".\n"
  "\nArguments: \n"
  "1. \"statistic\" (string, required) Specify what statistic you want\n"
  "2. \"series\" (string, optional) Specify what data series you want. Options are "
  