Ref T650, using FSX SimulatedObject type decrease exeption counter when successfully added

* normally adding the SimObject fails first,
* then the workaround is used (but exception counter is 1)
* this means a 2nd time the object cannot be changed, as there is already a counter number > 0

src/plugins/simulator/fsxcommon/simconnectobject.h

@@ -250,6 +250,9 @@ namespace BlackSimPlugin
             //! Increase adding exception
             void increaseAddingExceptions() { m_addingExceptions++; }
 
+            //! Decrease adding exception
+            void decreaseAddingExceptions() { if (m_addingExceptions > 0) { m_addingExceptions--; } ; }
+
             //! Adding and directly removed
             int getAddingDirectlyRemoved() const { return m_addingDirectlyRemoved; }