Be specific about exceptions to ignore

Author: softins

Lib/mailbox.py

@@ -755,7 +755,7 @@ def flush(self):
         os.chmod(new_file.name, info.st_mode)
         try:
             os.chown(new_file.name, info.st_uid, info.st_gid)
-        except:
+        except (AttributeError, OSError):
             pass
         try:
             os.rename(new_file.name, self._path)