Have check_sysctl populated on all hosts

It was populated wrongly in 5f07e69 on the icinga host(s) but this needs to
be executed via NRPE on the actual host being monitored. Moving it to
the base module and have it populated on all hosts

Change-Id: I8777d94d846e0c70a3f532bd80c9be921ad82b86
Merge "Have check_sysctl populated on all hosts" into production