Core/Dependencies: Remove ACE_Singleton dependency from the Log and DelayExecutor classes.

Removed an unused function.

src/server/shared/Threading/DelayExecutor.cpp

@@ -6,7 +6,8 @@
 
 DelayExecutor* DelayExecutor::instance()
 {
-    return ACE_Singleton<DelayExecutor, ACE_Thread_Mutex>::instance();
+    static DelayExecutor* instance = new DelayExecutor();
+    return instance;
 }
 
 DelayExecutor::DelayExecutor()