Fixed discord link

Author: abalyasnikov

README.md

@@ -9,7 +9,7 @@
 
 **DeFi SDK** is an open-source system of smart contracts that allows you to execute trades with ERC20 tokens and track balances on different protocols.
 
-If you have any questions about DeFi SDK, feel free to reach out to us on our [Discord server](https://go.zerion.io/discord).
+If you have any questions about DeFi SDK, feel free to reach out to us on our [Discord server](https://zerion.io/discord).
 
 ![](https://i.ibb.co/RC54SjL/defisdk.png)