Update sendfrom RPC help to correct coin selection misconception

Author: ryanofsky

src/wallet/rpcwallet.cpp

@@ -819,6 +819,9 @@ UniValue sendfrom(const JSONRPCRequest& request)
             + HelpRequiringPassphrase() + "\n"
             "\nArguments:\n"
             "1. \"fromaccount\"       (string, required) The name of the account to send funds from. May be the default account using \"\".\n"
+            "                       Specifying an account does not influence coin selection, but it does associate the newly created\n"
+            "                       transaction with the account, so the account's balance computation and transaction history can reflect\n"
+            "                       the spend.\n"
             "2. \"toaddress\"         (string, required) The bitcoin address to send funds to.\n"
             "3. amount                (numeric or string, required) The amount in " + CURRENCY_UNIT + " (transaction fee is added on top).\n"
             "4. minconf               (numeric, optional, default=1) Only use funds with at least this many confirmations.\n"