Update index.html

Author: Rusiek

index.html

@@ -124,7 +124,7 @@ <h4><strong>Unit8 - MLOPS w chmurze</strong> <br/>Kiedy: 8 listopada, godzina 18
 	<a href="https://calendar.google.com/calendar/u/2?cid=c3Y2OWh0dTVpcW9tYjF2bjN1NmU3YnVsZ2tAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ">
           <img src="assets/Google_Calendar-Logo.wine-modified.png" alt="CAL" width="64" height="64" />
         </a>
-        <a href="bit.do/knbit-discord">
+        <a href="https://bit.do/knbit-discord">
           <img src="assets/discord-logo.png" alt="AGH" width="64px" height="64px" />
         </a>
         <a href="https://www.agh.edu.pl/">