Make sure --statsd-port is an int
Make sure --statsd-port is an int

Summary:
Something 4 layers deep expects an int at runtime.
I'd meant to mypy this again, which would've saved me from having to discover this on staging.

Test Plan: Staging

Reviewers: josiah

Reviewed By: josiah

Subscribers: changesbot

Differential Revision: https://tails.corp.dropbox.com/D156718

dropbox/changes-mesos-framework,dropbox/changes-mesos-framework