Read max_toot_chars from root object. Fixes #297.

max_toot_chars is present in the root of the initial state object.
(Previously, we were trying to read it from the meta child object.)

app/javascript/flavours/glitch/util/initial_state.js

@@ -18,6 +18,6 @@ export const boostModal = getMeta('boost_modal');
 export const favouriteModal = getMeta('favourite_modal');
 export const deleteModal = getMeta('delete_modal');
 export const me = getMeta('me');
-export const maxChars = getMeta('max_toot_chars') || 500;
+export const maxChars = initialState['max_toot_chars'] || 500;
 
 export default initialState;