Add a setup warning for port in mysql.host
Summary:
A pull from GitHub recently added mysql.port, for explicitly configuring the MySQL port. See:
Add a setup warning for old-style configurations (which will still work properly), to get them to move to the new style.
Test Plan: {F50113}
Reviewers: btrahan, chad
Reviewed By: chad
CC: aran
Differential Revision: https://secure.phabricator.com/D6449