MFH: r465913

www/node4: Update 4.8.7_1 -> 4.9.0

This is a security release addressing multiple vulnerabilities. Users
are recommended to upgrade as soon as possible.

https://nodejs.org/en/blog/vulnerability/march-2018-security-releases/
https://nodejs.org/en/blog/release/v4.9.0/

Security: 5a9bbb6e-32d3-11e8-a769-6daaba161086

Approved by: ports-secteam (riggs)