Don't add 'the' to `will_continue_on` text

www.agileplannerapp.com/boards/173808/cards/8718

.. for business support editions. instead, give editors
flexibility to add that word from mainstream Publisher.
This keeps it consistent with other formats.
Merge pull request #695 from alphagov/fix-the-the

Don't add 'the' to `will_continue_on` text