Quick bug fix. There is a race in DKV store in case a thread gets a reference for a value which is persisted on Ice locally and the data is not in RAM, and before it accesses the data another thread removes the value from the DKV store (the disk copy is removed in this case), then when the original thread accesses the value it gets FileNotFoundException.

For now only quick fix:
   removed assert exposing the race + not removing local cache copy of objects in case they're already persisted.

This does not fix the race but hopefully will hide it for a while until there is long term solution.