rpc, wallet, refactor: Remove non-descriptor errors

It is not possible to load a legacy/ non-descriptor wallet anymore
so no need to check for WALLET_FLAG_DESCRIPTORS in RPC calls, even when
passing -rpcwallet/ JSON `/wallet/<walletname>/` endpoint, that searches
for the wallets loaded already in the context.

Author: pablomartin4btc

src/wallet/rpc/backup.cpp

@@ -356,11 +356,6 @@ RPCHelpMan importdescriptors()
     // the user could have gotten from another RPC command prior to now
     wallet.BlockUntilSyncedToCurrentChain();
 
-    //  Make sure wallet is a descriptor wallet
-    if (!pwallet->IsWalletFlagSet(WALLET_FLAG_DESCRIPTORS)) {
-        throw JSONRPCError(RPC_WALLET_ERROR, "importdescriptors is not available for non-descriptor wallets");
-    }
-
     WalletRescanReserver reserver(*pwallet);
     if (!reserver.reserve(/*with_passphrase=*/true)) {
         throw JSONRPCError(RPC_WALLET_ERROR, "Wallet is currently rescanning. Abort existing rescan or wait.");
@@ -493,10 +488,6 @@ RPCHelpMan listdescriptors()
     const std::shared_ptr<const CWallet> wallet = GetWalletForJSONRPCRequest(request);
     if (!wallet) return UniValue::VNULL;
 
-    if (!wallet->IsWalletFlagSet(WALLET_FLAG_DESCRIPTORS)) {
-        throw JSONRPCError(RPC_WALLET_ERROR, "listdescriptors is not available for non-descriptor wallets");
-    }
-
     const bool priv = !request.params[0].isNull() && request.params[0].get_bool();
     if (priv) {
         EnsureWalletIsUnlocked(*wallet);

src/wallet/rpc/wallet.cpp

@@ -763,10 +763,6 @@ RPCHelpMan gethdkeys()
             const std::shared_ptr<const CWallet> wallet = GetWalletForJSONRPCRequest(request);
             if (!wallet) return UniValue::VNULL;
 
-            if (!wallet->IsWalletFlagSet(WALLET_FLAG_DESCRIPTORS)) {
-                throw JSONRPCError(RPC_WALLET_ERROR, "gethdkeys is not available for non-descriptor wallets");
-            }
-
             LOCK(wallet->cs_wallet);
 
             UniValue options{request.params[0].isNull() ? UniValue::VOBJ : request.params[0]};
@@ -865,11 +861,6 @@ static RPCHelpMan createwalletdescriptor()
             std::shared_ptr<CWallet> const pwallet = GetWalletForJSONRPCRequest(request);
             if (!pwallet) return UniValue::VNULL;
 
-            //  Make sure wallet is a descriptor wallet
-            if (!pwallet->IsWalletFlagSet(WALLET_FLAG_DESCRIPTORS)) {
-                throw JSONRPCError(RPC_WALLET_ERROR, "createwalletdescriptor is not available for non-descriptor wallets");
-            }
-
             std::optional<OutputType> output_type = ParseOutputType(request.params[0].get_str());
             if (!output_type) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Unknown address type '%s'", request.params[0].get_str()));