fixes #4109: correct rudder agent cron name to be compliant with
dh_installcron
Merge pull request #172 from VinceMacBuche/bug/4109

fixes #4109: correct rudder agent cron name to be compliant with
Merge branch 'branches/rudder/2.6' into branches/rudder/2.7
Merge branch 'branches/rudder/2.7' into branches/rudder/2.8