Remove outdated comment

src/api/core/ciphers.rs

@@ -320,7 +320,6 @@ fn post_collections_admin(uuid: String, data: Json<CollectionsAdminData>, header
     let posted_collections: HashSet<String> = data.collectionIds.iter().cloned().collect();
     let current_collections: HashSet<String> = cipher.get_collections(&conn).iter().cloned().collect();
 
-    //TODO: update cipher collection mapping
     for collection in posted_collections.symmetric_difference(&current_collections) {
         match Collection::find_by_uuid(&collection, &conn) {
             None => (), // Does not exist, what now?