docs: incorrect link reference in 03_withdrawals.md (#354)

# What ❔

- incorrect link reference in 03_withdrawals.md

## Why ❔

- incorrect link reference in 03_withdrawals.md

## Checklist

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docs/advanced/03_withdrawals.md

@@ -79,12 +79,13 @@ address constant L2_ETH_TOKEN_SYSTEM_CONTRACT_ADDR = address(0x800a);
 
 This is a good opportunity to talk about system contracts that are automatically deployed on L2. You can find the full
 list here
-[in github](https://github.com/matter-labs/system-contracts/blob/436d57da2fb35c40e38bcb6637c3a090ddf60701/scripts/constants.ts#L29)
+[in github](https://github.com/matter-labs/era-system-contracts/blob/436d57da2fb35c40e38bcb6637c3a090ddf60701/scripts/constants.ts#L29)
 
 This is the place were we specify that `bootloader` is at address 0x8001, `NonceHolder` at 0x8003 etc.
 
-This brings us to [L2EthToken.sol](https://github.com/matter-labs/system-contracts/blob/main/contracts/L2EthToken.sol)
-that has the implementation of the L2 Eth.
+This brings us to
+[L2EthToken.sol](https://github.com/matter-labs/era-system-contracts/blob/main/contracts/L2EthToken.sol) that has the
+implementation of the L2 Eth.
 
 When we look inside, we can see: