issue: ENG-5766
We don't want to remove lastUserInteractionCalendar for users using CSAT.
The rest of the reducer is already correct, because it checks new threads aand based on that removes entries. So if thread reducer removes threads related to the keyserver, the entires will be removed as well

Tested that if a user is connected to another keyserver and logs out of it, the corresponding entires are indeed removed. Tested that for a user not using CSAT, lastUserInteractionCalendar is still reset to 0