Zabbix: put in a note about trigger prototype dependency

roles/os_zabbix/vars/template_os_linux.yml

@@ -264,6 +264,7 @@ g_template_os_linux:
     priority: high
 
   # This has a dependency on the previous trigger
+  # Trigger Prototypes do not work in 2.4.  They will work in Zabbix 3.0
   - name: 'Filesystem: {#OSO_FILESYS} has less than 15% free disk space on {HOST.NAME}'
     expression: '{Template OS Linux:disc.filesys.full[{#OSO_FILESYS}].last()}>85'
     url: 'https://github.com/openshift/ops-sop/blob/master/V3/Alerts/check_filesys_full.asciidoc'
@@ -276,6 +277,8 @@ g_template_os_linux:
     url: 'https://github.com/openshift/ops-sop/blob/master/V3/Alerts/check_filesys_full.asciidoc'
     priority: high
 
+  # This has a dependency on the previous trigger
+  # Trigger Prototypes do not work in 2.4.  They will work in Zabbix 3.0
   - name: 'Filesystem: {#OSO_FILESYS} has less than 10% free inodes on {HOST.NAME}'
     expression: '{Template OS Linux:disc.filesys.inodes.pused[{#OSO_FILESYS}].last()}>90'
     url: 'https://github.com/openshift/ops-sop/blob/master/V3/Alerts/check_filesys_full.asciidoc'