Upgrade passenger and its third-party modules for www/nginx and
www/nginx-devel from 5.3.7 to 6.0.0.

<ChangeLog>

• Introduces support for *all* programming languages. Yes that's right... Java, Elixir, Go — Passenger now supports them all! This effort is called "generic language support".
• Bumps the preferred Nginx version to 1.15.7.
• Introduces anonymous usage telemetry, which helps us improve Passenger. Please read the docs on what data is collected and how to disable this.
• [Nginx] Introduces a new option "passenger_request_buffering on|off", to allow disabling request body buffering. This is only supported in Nginx >= 1.15.3. Closes GH-2121.
• Updated various library versions used in precompiled binaries (used for e.g. gem installs):
  • OpenSSL: 1.0.2q (was: 1.0.2p)
  • libcurl: 7.62.0 (was: 7.61.1)
  • Ruby: 2.3.8 (was: 2.3.7)

</ChangeLog>