Fixed timer crash once for all - yes it was a race condition

Barotrauma/BarotraumaShared/SharedSource/LuaCs/LuaCsTimer.cs

@@ -60,6 +60,8 @@ namespace Barotrauma
                 throw new ArgumentNullException(nameof(timedAction));
             }
 
+            lock (timedActions)
+            {
                 int insertionPoint = timedActions.BinarySearch(timedAction, new TimerComparer());
 
                 if (insertionPoint < 0)
@@ -69,8 +71,11 @@ namespace Barotrauma
 
                 timedActions.Insert(insertionPoint, timedAction);
             }
+        }
 
         public void Update()
+        {
+            lock (timedActions)
             {
                 TimedAction[] timedCopy = timedActions.ToArray();
                 for (int i = 0; i < timedCopy.Length; i++)
@@ -95,6 +100,7 @@ namespace Barotrauma
                     }
                 }
             }
+        }
 
         public void Clear()
         {