Clean up also files with identical modification dates
Clean up also files with identical modification dates

Only one of them was cleaned up until now. The client touches many files
in parallel and the precision of System.currentTimeMillis() may not be
perfect resulting identical modification dates.  
chipster/chipster,chipster/chipster,chipster/chipster,chipster/chipster,chipster/chipster,chipster/chipster,chipster/chipster,chipster/chipster,chipster/chipster,chipster/chipster