Excluded Fedora and RHEL from EPEL install task

Fedora includes most EPEL packages inside of their default repo, they also do not have a epel package,
Redhat does not offer a EPEL package by default on their repository

roles/netbootxyz/tasks/generate_disks_base.yml

@@ -16,7 +16,8 @@
     yum:
       name: epel-release
       state: present
-    when: ansible_os_family == "RedHat"
+    when:
+      - ansible_distribution == "CentOS"
 
   - name: Set var to bootloader of loop
     set_fact: