[Cashtab] Bump extension version to update published version to latest master

Summary: Will be refactoring Cashtab to use ecash-lib. Publish most recent version of extension first.

Test Plan: npm test

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Differential Revision: https://reviews.bitcoinabc.org/D16159