[pkg-go] prometheus-mysqld-exporter is marked for autoremoval from testing

[Debian testing autoremoval watch]

prometheus-mysqld-exporter 0.9.0+ds-3 is marked for autoremoval from testing on 2017-09-18

It (build-)depends on packages with these RC bugs:
870843: golang-github-sirupsen-logrus-dev: golang-github-armon-go-metrics-dev: unhandled symlink to directory conversion: /usr/share/gocode/src/github.com/sirupsen/logrus -> ../Sirupsen/logrus