Reload nginx after any configuration file is updated

Summary:
Currently, only nginx.conf triggers a nginx reload.

Yet, we can add a new configuration file, e.g. for a new vhost
or amend an existing one, and that should trigger a reload too.

Fixes T1185.

Test Plan: Change configuration (e.g. D956) and ensure it works

Reviewers: jokerozen, Sandlayth, dereckson

Reviewed By: dereckson

Maniphest Tasks: T1185

Differential Revision: https://devcentral.nasqueron.org/D955