fix seed breaking from UsersFetcher changes

app/workers/libraries_fetcher.rb

@@ -1,7 +1,7 @@
 class LibrariesFetcher
   include Sidekiq::Worker
 
-  def perform(game_ids, library_id)
+  def perform(game_ids, library_id = nil)
     game_ids.each_slice(100) do |slice|
       GamesFetcher.perform_async(slice, library_id)
     end

app/workers/users_fetcher.rb

@@ -1,12 +1,13 @@
 class UsersFetcher
   include Sidekiq::Worker
 
-  def perform(bgg_username,library_id)
-    library = Library.find_by(id: library_id)
+  def perform(bgg_username,library_id = nil)
+    library = Library.find_by(id: library_id) if library_id
     bgg_user_library = BggApi.new.collection({ username: bgg_username })
-    existing_games_array = library.games.map { |game| game.bgg_id }
+    existing_games_array = []
+    existing_games_array += library.games.map { |game| game.bgg_id } if library
     collection_array = bgg_user_library["item"].map { |game| game["objectid"].to_i }
     collection_array -= existing_games_array
-    LibrariesFetcher.perform_async(collection_array, library.id)
+    LibrariesFetcher.perform_async(collection_array, library_id)
   end
 end