Removing duplicate gather_facts in playbooks

This was introduced in I348a4b7dfe70d56a64899246daf65ea834a75d2a

Ansible complains with:

[WARNING]: While constructing a mapping from /opt/openstack-ansible/playbooks
/lxc-containers-create.yml, line 16, column 3, found a duplicate dict key
(gather_facts).  Using last defined value only.

Change-Id: I0cb978aa7b434568406a38c71da2e4bb1e1549cc

playbooks/lxc-containers-create.yml

@@ -15,9 +15,8 @@
 
 - name: Create container(s)
   hosts: "{{ container_group|default('all_containers') }}"
-  gather_facts: "{{ gather_facts | default(True) }}"
-  max_fail_percentage: 20
   gather_facts: false
+  max_fail_percentage: 20
   user: root
   roles:
     - { role: "lxc_container_create", tags: [ "lxc-container-create" ] }

playbooks/lxc-containers-destroy.yml

@@ -15,9 +15,8 @@
 
 - name: Destroy lxc containers
   hosts: "{{ container_group|default('all_containers') }}"
-  gather_facts: "{{ gather_facts | default(True) }}"
-  max_fail_percentage: 20
   gather_facts: false
+  max_fail_percentage: 20
   user: root
   tasks:
     - name: Destroy a container