wallet, rpc:remove settxfee and paytxfee

src/wallet/feebumper.cpp

@@ -61,7 +61,7 @@ static feebumper::Result CheckFeeRate(const CWallet& wallet, const CMutableTrans
 {
     // check that fee rate is higher than mempool's minimum fee
     // (no point in bumping fee if we know that the new tx won't be accepted to the mempool)
-    // This may occur if the user set fee_rate or paytxfee too low, if fallbackfee is too low, or, perhaps,
+    // This may occur if fallbackfee is too low, or, perhaps,
     // in a rare situation where the mempool minimum fee increased significantly since the fee estimation just a
     // moment earlier. In this case, we report an error to the user, who may adjust the fee.
     CFeeRate minMempoolFeeRate = wallet.chain().mempoolMinFee();