go_1_9: 1.9.4 -> 1.9.5

This is a maintenance bump of the golang 1.9 version.

Within the updates are a few bug fixes including an (extended?)
fix for CVE-2018-7187 [1].

The complete changelog is available at the golang GitHub project [2].

[1] https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-7187
[2] https://github.com/golang/go/issues?q=milestone%3AGo1.9.5