rpc: fix code comment for bumpfee/psbtbumpfee output

Author: jonatack

src/wallet/rpcwallet.cpp

@@ -3526,8 +3526,8 @@ static RPCHelpMan bumpfee_helper(std::string method_name)
 
     UniValue result(UniValue::VOBJ);
 
-    // If wallet private keys are enabled, return the new transaction id,
-    // otherwise return the base64-encoded unsigned PSBT of the new transaction.
+    // For bumpfee, return the new transaction id.
+    // For psbtbumpfee, return the base64-encoded unsigned PSBT of the new transaction.
     if (!want_psbt) {
         if (!feebumper::SignTransaction(*pwallet, mtx)) {
             throw JSONRPCError(RPC_WALLET_ERROR, "Can't sign transaction.");