Revert "[Cashtab] Add privacy policy"

Summary:
This reverts commit c4fefd9248fc4287689438888cb410664fc35e2b.

Remove privacy policy. Replacement generated, link does not need to be in the app.

Test Plan: npm start and observe link is out.

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Differential Revision: https://reviews.bitcoinabc.org/D11134