Update continue/break for php 7.3

Summary:
Fixes https://discourse.phabricator-community.org/t/error-on-project-creation-or-edition-with-php7-3/2236

I didn't actually repro this because I don't have php 7.3 installed. I'm also not sure if the break; break was intentional or not, since I'm not sure you could ever reach two consecutive break statements.

Test Plan: Created some projects. Didn't actually try to hit the code that fires if you're making a project both a subproject and a milestone.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D19925