Fix crash if list is empty

LobbyServer/ScoresManager.cs

@@ -23,18 +23,24 @@ namespace LobbyServer
             else
             {
                 _scores = new List<ScoreEntry>();
+                _scores.Add(new ScoreEntry("QuadraLudi", 0));
             }
         }
 
         public void Add(ScoreEntry entry)
         {
             _scores.Add(entry);
-            _scores.OrderByDescending(x => x.Score);
+            Sort();
         }
 
         public void Save()
         {
             File.WriteAllText(FilePath, JsonConvert.SerializeObject(_scores));
         }
+
+        private void Sort()
+        {
+            _scores = _scores.OrderByDescending(x => x.Score).ToList();
+        }
     }
 }