Update withdraw-gateways.mdx (#231)

fix the typo of mistyped L2 and L1

Author: floydlin

src/content/docs/en/technology/bridge/withdraw-gateways.mdx

@@ -59,7 +59,7 @@ The withdrawal of ETH token works as follows.
 
 The withdraw of ERC20 tokens works as follows.
 
-1. To withdraw ERC20 tokens from L1 to L2, users can use `L2GatewayRouter.withdrawERC20` and `L2GatewayRouter.withdrawERC20AndCall` showed below.
+1. To withdraw ERC20 tokens from L2 to L1, users can use `L2GatewayRouter.withdrawERC20` and `L2GatewayRouter.withdrawERC20AndCall` showed below.
 
     ```solidity
     function withdrawERC20(address _token, uint256 _amount, uint256 _gasLimit) external payable;