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

[Debian testing autoremoval watch]

prometheus-mysqld-exporter 0.11.0+ds-1 is marked for autoremoval from testing on 2020-03-23

It is affected by these RC bugs:
952291: prometheus-mysqld-exporter: FTBFS: src/github.com/prometheus/mysqld_exporter/mysqld_exporter.go:227:31: undefined: prometheus.InstrumentHandlerFunc
953040: prometheus-mysqld-exporter: Regression on configuration disallows proper use of mysql auth_socket authentication