Add explicit include directory to zabbix server.

For my opinion - it is good way to explicitly declare 'include'
directories to services, so I removed old non-working conditional
statement about it at all rather then recreate new one.

Change-Id: I4e973b1f8f6ec94bd0840a6f69035fe03121192e
Closes-Bug: #1382353
Merge "Add explicit include directory to zabbix server."