Title: Avoid warning in cmc.log when rescheduling non-existing discovery check
Level: 1
Component: core
Compatible: compat
Version: 1.2.8b12
Date: 1461077110
Class: fix

This avoids the folloing message:
F+:var/log/cmc.log
2016-04-19 13:49:24 [4] Ignoring command SCHEDULE_FORCED_SVC_CHECK;10.1.1.199;Check_MK Discovery;1461066564: invalid parameters
F-:
