Update: Replace deprecated ansible_os_family with ansible_facts.os_family

- x2go-server.yml: Updated condition to use ansible_facts.os_family
- upgrade.yml: Updated all conditions and commented lines
- caching-nameserver.yml: Updated RedHat OS family checks

Fixes deprecation warning in Ansible 2.12+

upgrade.yml

@@ -6,21 +6,21 @@
 
    - name: Update packages list
      apt: update_cache=yes
-     when: ansible_os_family == 'Debian'
+     when: ansible_facts.os_family == 'Debian'
 
    - name: List packages to upgrade (1/2)
      shell: aptitude -q -F%p --disable-columns search "~U"
      register: updates
      changed_when: False
-     when: ansible_os_family == 'Debian'
+     when: ansible_facts.os_family == 'Debian'
 
    - name: List packages to upgrade (2/2)
      debug: msg="{{ updates.stdout_lines | count }} packages to upgrade ({{ updates.stdout_lines | join(', ') }})"
-     when: (ansible_os_family == 'Debian' and updates.stdout_lines)
+     when: (ansible_facts.os_family == 'Debian' and updates.stdout_lines)
 
    - name: Upgrade packages
      apt: upgrade=safe
-     when: ansible_os_family == 'Debian'
+     when: ansible_facts.os_family == 'Debian'
 
    - name: Check what the new version is
      shell:  lsb_release -r | awk '{print $2}'
@@ -43,11 +43,11 @@
 
 #   - name: list services to restart (3/3)
 #     debug: msg="{{ services.stdout_lines | count }} services to restart ({{ services.stdout_lines | join (", ") }})"
-#     when: (ansible_os_family == 'Debian' and services.stdout_lines)
+#     when: (ansible_facts.os_family == 'Debian' and services.stdout_lines)
 
 #   - name: list services to restart (2/3)
 #     debug: msg="{{ services.stdout_lines | count }} services to restart ({{ services.stdout_lines | join (", ") }})"
-#     when: (ansible_os_family == 'Debian' and services.stdout_lines)
+#     when: (ansible_facts.os_family == 'Debian' and services.stdout_lines)
 
    - name: cache cleanup
      shell: apt-get autoclean