only fetch privileged resources when appropriate

always doing these fetches regardless of whether they'll reasonably
succeed is silly and causes a bunch of spurious 403's, which end up as
noise in the server logs. instead, let's not do that.

src/boot/after_store.js

@@ -399,6 +399,14 @@ const afterStoreSetup = async ({ store, i18n }) => {
   ])
 
   // Start fetching things that don't need to block the UI
+  const currentUser = store.state.users.currentUser
+  if (currentUser) {
+    store.dispatch('fetchMutes')
+    store.dispatch('startFetchingAnnouncements')
+    if (currentUser.role === 'admin' || currentUser.role === 'moderator') {
+      store.dispatch('startFetchingReports')
+    }
+  }
   getTOS({ store })
   getStickers({ store })