[native] Remove setThreadStoreLoaded(true) early return in SQLiteContextProvider

Summary:
This early return was needed before persistConfig.version was bumped to 30 so the migration could be tested in DEV without breaking things for any general releases made before this work was complete.

Since the persistConfig.version has been bumped, there's no possibility that a new client would have a persistConfig.version < 30, so this branch will never be hit.

Test Plan: NA, not sure how to test

Reviewers: def-au1t, palys-swm

Reviewed By: palys-swm

Subscribers: ashoat, Adrian, yayabosh

Differential Revision: https://phabricator.ashoat.com/D4158