apache-httpd/zabbix: Allow custom configFile.

If option is left by its default value, behaviour is the same as before, using
the configuration file created by the web interface.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
apache-httpd/zabbix: Set max_input_time.

At least the Zabbix 2.x web installer requires max_input_time to be set to 300
seconds. As it doesn't hurt to set it for the 1.x versions, I'm including it
here.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>