Show the room avatar rather than the user avatar in the header

It's supposed to be the room avatar; this was a regression introduced during the LiveKit hack week.

src/room/GroupCallView.tsx

@@ -35,6 +35,7 @@ import { PosthogAnalytics } from "../analytics/PosthogAnalytics";
 import { useProfile } from "../profile/useProfile";
 import { UserChoices } from "../livekit/useLiveKit";
 import { findDeviceByName } from "../media-utils";
+import { useRoomAvatar } from "./useRoomAvatar";
 
 declare global {
   interface Window {
@@ -81,12 +82,14 @@ export function GroupCallView({
   }, [groupCall]);
 
   const { displayName, avatarUrl } = useProfile(client);
+  const roomAvatarUrl = useRoomAvatar(groupCall.room);
 
   const matrixInfo: MatrixInfo = {
     userName: displayName,
     avatarUrl,
     roomName: groupCall.room.name,
     roomIdOrAlias,
+    roomAvatarUrl,
   };
 
   useEffect(() => {