Checkmk Werk 13229: Drop support for creation of ServiceLabels in legacy plugins

ID: 13229 Title: Drop support for creation of ServiceLabels in legacy plugins Component: Checks & agents Level: 1 Class: New feature Version: 2.1.0i1 This werk only affect users who have implemented their own pre Checkmk 2.0 check plugins (those in <tt>local/share/check_mk/checks</tt>) *and* where creating ServiceLabels. Plugins trying to create ServiceLabel instances will fail with a NameError. The afore mentioned feature is no longer supported. Creation of service labels can now only be implemented using the new check API. For details please refer to the Sphinx documentation of the <tt>Service</tt> and <tt>ServiceLabel</tt> classes in the "Help" menu of your Checkmk site.