Fixes #4281: disable RepeatedMsgReduction in rudder rsyslog conf

http://www.rudder-project.org/redmine/issues/4281

We can disable Directive repeatedMsgReduction here, it will not impact configuration in /etc/rsyslog.conf and will disable it for rudder related message

See: http://stackoverflow.com/questions/20542758/rsyslog-conditional-repeatedmsgreduction