Small fix for python 3.2

Change-Id: Icbfb25afa3f750ac98ac5cdd4dcd68cf24fbad61

Author: Vespian

test/moduletests/check_growth/test_check_growth.py

@@ -450,7 +450,7 @@ def setUp(self):
 
         try:
             os.unlink(self.history_file)
-        except FileNotFoundError:
+        except (OSError, IOError):
             pass
 
         check_growth.HistoryFile.init(self.history_file, self.max_averaging_window,