current release candidate can't restart zabbix agent service

[ITler]

Affected Puppet, Ruby, OS and module versions/distributions

• Puppet: 4.3.2
• Ruby: ruby 2.1.8p440 (2015-12-16 revision 53160) [x86_64-linux]
• Distribution: Ubuntu 14 LTS
• Module version: b802fa7 2.3.3-rc0

How to reproduce (e.g Puppet code you use)

include zabbix::agent

What are you seeing

New ´systemctl´ implementation not working correctly for Ubuntu 14 LTS for particular use case:

Unable to restart zabbix agent service after changes to zabbix agent configuration were made.
(zabbix agent was already provisioned by puppet beforehand)
This also results in deletion of startup scripts... This also affects zabbix server startup script

What behaviour did you expect instead

service restart works

Output log

Error: /Stage[main]/Systemd/Exec[systemctl-daemon-reload]: Failed to call refresh: Could not find command 'systemctl'
Error: /Stage[main]/Systemd/Exec[systemctl-daemon-reload]: Could not find command 'systemctl'
Error: /Stage[main]/Zabbix::Agent/Service[zabbix-agent]: Could not evaluate: Could not find init script or upstart conf file for 'zabbix-agent'
Error: /Stage[main]/Zabbix::Agent/Service[zabbix-agent]: Failed to call refresh: Could not find init script or upstart conf file for 'zabbix-agent'
Error: /Stage[main]/Zabbix::Agent/Service[zabbix-agent]: Could not find init script or upstart conf file for 'zabbix-agent'

[jk2l]

This is duplicate issue of #252 working a fix with them