fix: set l1 token mainnet address

Author: JuArce

claim_contracts/base/.env.example

@@ -14,7 +14,7 @@ L1_MAINNET_RPC_URL=https://ethereum-rpc.publicnode.com
 # Token addresses
 L1_TOKEN_SEPOLIA=0xd2Fd114f098b355321cB3424400f3CC6a0d75C9A
 L2_TOKEN_SEPOLIA=0x4AAcFbc2C31598a560b285dB20966E00B73F9F81
-L1_TOKEN_MAINNET=
+L1_TOKEN_MAINNET=0x50614cc8e44f7814549c223aa31db9296e58057c
 L2_TOKEN_MAINNET=
 
 # Bridge addresses (source: https://docs.base.org/chain/base-contracts)