Added guards in create object initialization to prevent memory leaks (#664)

src/bacnet/basic/object/lo.c

@@ -2462,5 +2462,7 @@ void Lighting_Output_Cleanup(void)
  */
 void Lighting_Output_Init(void)
 {
-    Object_List = Keylist_Create();
+    if (!Object_List) {
+        Object_List = Keylist_Create();
+    }
 }