openqa/server: allow createhdds to fail

It does, sometimes, and that probably shouldn't stop the play.
We likely already have some older images, and even if this is
the *first* creation, we can go ahead with the rest of the
deployment safely enough, and debug the image creation problem
later.

roles/openqa/server/tasks/main.yml

@@ -161,6 +161,7 @@
 - name: Create hard disk images (this may take a long time!)
   command: "/etc/cron.daily/createhdds"
   when: "diskcheck.rc > 1"
+  ignore_errors: yes
 
 - name: Create exports file
   copy: src=exports dest=/etc/exports.d/openqa.exports owner=root group=root mode=0644