fix: pubsub should be initialized with useState (#400)

Dont need to use `useEffect` separately to initialize use state

fixes: https://sendbird.atlassian.net/browse/UIKIT-2825

Author: Sravan S

src/lib/Sendbird.jsx

@@ -63,16 +63,12 @@ export default function Sendbird(props) {
     isREMUnitEnabled = false,
   } = config;
   const [logger, setLogger] = useState(LoggerFactory(logLevel));
-  const [pubSub, setPubSub] = useState();
+  const [pubSub] = useState(pubSubFactory());
   const [sdkStore, sdkDispatcher] = useReducer(sdkReducers, sdkInitialState);
   const [userStore, userDispatcher] = useReducer(userReducers, userInitialState);
 
   useTheme(colorSet);
 
-  useEffect(() => {
-    setPubSub(pubSubFactory());
-  }, []);
-
   useEffect(() => {
     logger.info('App Init');
     // dispatch action