[native] Remove connection from persist black list

Summary:
issue: ENG-4933
connection was moved to kyeserverStore some time ago, and we make sure it's not persisted using transforms. BEcause it's not a top level value anymore, this code wasn't doing anything.

Test Plan:
this was dead code, because connection field is not in top level of state anymore
closed and opend the app a couple of times, no errors showed up, checked that connection is not top level but in the keyserver store

Reviewers: michal, kamil, ginsu

Reviewed By: michal

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D11336