lookup.get_person_for_user: return cached result earlier
We inadvertently returned the cached return value for get_person_for_user after touching the database, not before.
Installing the silk profiler revealed that for each index request we were make 382 queries to the database when using a copy of database with ~1000 assets. This took around 200ms.
By re-ordering these statements, we have reduced the number of database queries to 5 which took around 10ms.
This is a 20x speedup.
I suggest we use silk going forward :).
Closes uisautomation/iar-deploy#25