The focus in “Subscribe to Firefox Monitor” pop-up is not in the “Subscribe with Email Account” field

[obotisan]

[Affected versions]:

• Firefox 62.0
• Firefox 64.0a1

[Affected Platforms]:

• Windows 10 x64
• macOS 10.13
• Ubuntu 16.04 x64

[Steps to reproduce]:

1. Navigate to https://fx-breach-alerts.herokuapp.com/
2. Click on the “Subscribe” button.
3. Start writing something without clicking in the “Subscribe with Email Account” field.

[Expected result]:

• The typed text appears in the “Subscribe with Email Account” field.

[Actual result]:

• Nothing happens.

[Regression]:

• I don't think this is a regression.

[CiprianGeorgiu]

Verified fixed on 62.0, under macOS 10.13, Ubuntu 16.04 and Windows 10 x64.