docs: remove unnecessary code (#1313)

Author: Now-Sprouting

docs/course/dev-connect.zh-CN.md

@@ -74,13 +74,6 @@ import { WagmiWeb3ConfigProvider } from "@ant-design/web3-wagmi";
 - import { Address } from "@ant-design/web3";
 + import { Address, NFTCard } from "@ant-design/web3";
 
-const config = createConfig({
-  chains: [mainnet],
-  transports: {
-    [mainnet.id]: http(),
-  },
-});
-
 export default function Web3() {
   return (
     <WagmiWeb3ConfigProvider>