Title: mysql mysql_capacity mysql_ping mysql_slave: Fixed broken service discovery when instance id is empty
Level: 1
Component: checks
Class: fix
Compatible: compat
State: unknown
Version: 1.2.7i3
Date: 1440682635

The mysql checks support monitoring multiple instances per host since some versions. There was a bug when
only a single instance is running on a host where an empty instance id is reported by the agent. The checks
were discoverying wrong service names and resulting in exceptions during checking.
