Disable gadgets caching

Re-parsing of config page takes approximately the same time as deserialization
from cache, however with caching you're just putting an extra load on memcached.

The bug that made this experiment fail last time has since been fixed by Legoktm.

Change-Id: I9c1f4f0e086637d0d6fa907a6a4a4b4fbf2ac053
Merge "Disable gadgets caching"