Remove removed titles from title_hash

src/library/library.cr

@@ -159,7 +159,9 @@ class Library
 
     @title_ids.select! do |title_id|
       title = @title_hash[title_id]
-      title.examine
+      existence = title.examine
+      @title_hash.delete title_id unless existence
+      existence
     end
     remained_title_dirs = @title_ids.map { |id| title_hash[id].dir }