Fix: There was an issue fetching the favorite status of this dashboard #6824 (#8013)

Issue: When Superset is running behind a reverse proxy and the dashboard page is requested with HTTPS protocol, the frontend can't retrieve the favorite status of the dashboard and, instead, displays the following toast message: 'There was an issue fetching the favorite status of this dashboard.'

Cause: While the API exposes the /favestar/Dashboard/{id}/count/ endpoint, the frontend executes an API call to /favestar/Dashboard/{id}/count, which leads to a redirect to an endpoint with HTTP protocol

Fix: Call the correct endpoint

superset/assets/src/dashboard/actions/dashboardState.js

@@ -64,7 +64,7 @@ export const FETCH_FAVE_STAR = 'FETCH_FAVE_STAR';
 export function fetchFaveStar(id) {
   return function fetchFaveStarThunk(dispatch) {
     return SupersetClient.get({
-      endpoint: `${FAVESTAR_BASE_URL}/${id}/count`,
+      endpoint: `${FAVESTAR_BASE_URL}/${id}/count/`,
     })
       .then(({ json }) => {
         if (json.count > 0) dispatch(toggleFaveStar(true));