Fix missing time import in fshandler.py

The Resource.__iter__ method uses time.sleep() but the time module
was not imported, causing GET requests to fail with NameError.

Author: pi-anl

pywebdav/server/fshandler.py

@@ -1,5 +1,6 @@
 import os
 import textwrap
+import time
 import logging
 import types
 import shutil