Fix ``Cache.get_many``
Fix ``Cache.get_many``

The ``map`` function behaviors differently between Python 2 and Python 3. In Python 3, you can't access the results returned by ``get_many`` with index.
mitsuhiko/werkzeug,pallets/werkzeug,fkazimierczak/werkzeug,fkazimierczak/werkzeug,fkazimierczak/werkzeug,mitsuhiko/werkzeug,pallets/werkzeug,pallets/werkzeug