message: init: Remove confusing and redundant InitError
  The "A fatal internal error occurred, see debug.log for details" is
  redundant because init.cpp will already show an InitError with a better
  error message as well as the hint to check the debug.log
diff: #include <httpserver.h>
  #include <rpc/protocol.h>
  #include <rpc/server.h>
  -#include <ui_interface.h>
  #include <util/strencodings.h>
  #include <util/system.h>
  #include <util/translation.h>
  @@ -251,9 +250,6 @@ static bool InitRPCAuthentication()
  {
  LogPrintf("Using random cookie authentication.\n");
  if (!GenerateAuthCookie(&strRPCUserColonPass)) {
  - uiInterface.ThreadSafeMessageBox(
  - _("Error: A fatal internal error occurred, see debug.log for details"), // Same message as AbortNode
  - "", CClientUIInterface::MSG_ERROR);
  return false;
  }
  } else {
  