Fix wasteful request to /api/v1/custom_emojis when not logged in (#22326)

app/javascript/mastodon/containers/mastodon.js

@@ -23,7 +23,9 @@ export const store = configureStore();
 const hydrateAction = hydrateStore(initialState);
 
 store.dispatch(hydrateAction);
-store.dispatch(fetchCustomEmojis());
+if (initialState.meta.me) {
+  store.dispatch(fetchCustomEmojis());
+}
 
 const createIdentityContext = state => ({
   signedIn: !!state.meta.me,