message: Fix warning message regarding min ring_size
diff: @@ -2498,7 +2498,7 @@ Value sendanontoanon(const Array& params, bool fHelp)
  "sendanontoanon <stealth_address> <amount> <ring_size> [narration] [comment] [comment-to]\n"
  "<amount> is a real number and is rounded to the nearest 0.000001\n"
  "<ring_size> is a number of outputs of the same amount to include in the signature\n"
  - " warning: using a ring_size less than 3 is not recommended"
  + " warning: using a ring_size less than 10 is not possible"
  + HelpRequiringPassphrase());
  if (pwalletMain->IsLocked())
  