Error in directory change notification (FindFirstChangeNotification) should be ignored

When using <file_order_source>, the Windows system call FindFirstChangeNotification could fail with "MSWIN-00000038 The network BIOS command limit has been reached". After this the directory was not polled for changes.

The JobScheduler is changed, that after such an error the directory is polled as usual. The error will be logged at level "debug". The system call is repeated later.