[Cashtab] Do not double call updateCashtabState on wallet change

Summary:
Depends on D17550

When we set it in state, this will cause the wallet to be written to storage when it has updated

We do not need to write it to storage and then write it again after it updates

Test Plan: npm test

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Differential Revision: https://reviews.bitcoinabc.org/D17551