Fixes missing data when retrieving multiple users, as in users/multi API endpoint

Adds missing SetCalculatedFields for cached users in GetIDs().

To test this, on a server using memcached, enable Simple API and access this endpoint:

/api/v1/users/multi.json?Users.ID=1,2,3,4,5 (or multiple UserIDs of your choice)

Where multiple listed users have the Photo field set (not null). Without the fix, the second+ queries should be missing PhotoUrl for cached users. With the fix, all PhotoUrls should return successfully every time.