RPC: Require descriptors=True for createwallet when BDB is not compiled

src/wallet/rpcwallet.cpp

@@ -2764,6 +2764,12 @@ static RPCHelpMan createwallet()
         warnings.emplace_back(Untranslated("Wallet is an experimental descriptor wallet"));
     }
 
+#ifndef USE_BDB
+    if (!(flags & WALLET_FLAG_DESCRIPTORS)) {
+        throw JSONRPCError(RPC_WALLET_ERROR, "Compiled without bdb support (required for legacy wallets)");
+    }
+#endif
+
     DatabaseOptions options;
     DatabaseStatus status;
     options.require_create = true;