Make settings for disabling ipv6 more flexible.

We should ignore errors on tasks that aren't fatal to execution
of the playbook and may not exit cleanly after the first time.

install/roles/logstash/tasks/main.yml

@@ -114,6 +114,7 @@
     - net.ipv6.conf.all.disable_ipv6
     - net.ipv6.conf.default.disable_ipv6
     - net.ipv6.conf.lo.disable_ipv6
+  ignore_errors: true
 
 - name: Determine if ipv6 is a loadable module
   command: /sbin/lsmod | grep ipv6 | grep -v nf
@@ -125,6 +126,7 @@
   notify:
     - rmmodipv6
   when: ansible_os_family == 'RedHat' and ipv6loadable.rc != 1
+  ignore_errors: true
 
 - include: ipv6-grub-disable.yml
 
@@ -142,6 +144,7 @@
     - restart Network
     - restart NetworkManager
   when: ansible_os_family == 'RedHat'
+  ignore_errors: true
 
 # X-Pack requires additional authentication
 - name: Load filebeat JSON index template (X-Pack enabled)