Brief flash of encrypted content when submitting a message

[brassy-endomorph]

Describe the bug

The original message flashes away, the armored PGP message appears, then the page submits/refreshes.

To Reproduce

1. Go to /profile/foo
2. Type message, fill out captcha
3. Submit

Expected behavior

The message submits without flashing altered text as this may confuse or worry the user

[glenn-sorrentino]

This is openpgp.js encrypting the text before sending for e2ee.

[brassy-endomorph]

It should be possible to intercept the click event and have the JS do the POST entirely so the user doesn't see the flash at all.

[glenn-sorrentino]

Rather not change it until we know it's a problem.