Fetchlimit test: update softquota limit to 380.

Fetchlimit test: update softquota limit to 380.
In the test the quota is set to 400, and softquota to 90%*400=360.
We first attach to quota, and then if we're above softquota we
drop the oldest client. With new socket code and taskmgr it's
parallel enough to create a race between multiple instances doing
'attach to quota' and then 'drop oldest client' - making number
of clients go over softquota. It's not a problem in real life, as
it's just soft quota.