Emails for contacts without postal addresses do not float

This was causing issues where the comment text would display oddly
next to the email address, and caused additional issues in IE.
Merge pull request #1708 from alphagov/fix-contact-email-display

Emails for contacts without postal addresses do not float

This was causing issues where the comment text would display oddly
next to the email address, and caused additional issues in IE.

Related Zendesk ticket: https://govuk.zendesk.com/agent/#/tickets/821859