Fix reserved name variable

The scale down actions appear to fail under newer versions of ansible if
the nodes are unavailable. In the logs we see:

[WARNING]: Found variable using reserved name: ignore_unreachable

This change renames our variable to not collide with ignore_unreachable

Change-Id: Ida54f59fc1415122241493c02a0fc764d09ae6c1

common/deploy-steps-playbooks-common.yaml

@@ -1,8 +1,8 @@
 - hosts: "{{ deploy_source_host }}"
   name: Gather facts from undercloud
   gather_facts: yes
-  any_errors_fatal: "{{ not ignore_unreachable | default(true) }}"
-  ignore_unreachable: "{{ ignore_unreachable | default(false) }}"
+  any_errors_fatal: "{{ not scale_ignore_unreachable | default(true) }}"
+  ignore_unreachable: "{{ scale_ignore_unreachable | default(false) }}"
   become: false
   tags:
     - facts
@@ -10,16 +10,16 @@
 - hosts: "{{ deploy_target_host }}"
   name: Gather facts from overcloud
   gather_facts: yes
-  any_errors_fatal: "{{ not ignore_unreachable | default(true) }}"
-  ignore_unreachable: "{{ ignore_unreachable | default(false) }}"
+  any_errors_fatal: "{{ not scale_ignore_unreachable | default(true) }}"
+  ignore_unreachable: "{{ scale_ignore_unreachable | default(false) }}"
   tags:
     - facts
 
 - hosts: all
   name: Load global variables
   gather_facts: "{{ gather_facts | default(false) }}"
-  any_errors_fatal: "{{ not ignore_unreachable | default(true) }}"
-  ignore_unreachable: "{{ ignore_unreachable | default(false) }}"
+  any_errors_fatal: "{{ not scale_ignore_unreachable | default(true) }}"
+  ignore_unreachable: "{{ scale_ignore_unreachable | default(false) }}"
   tasks:
     - include_vars: global_vars.yaml
       no_log: true

common/deploy-steps.j2

@@ -1163,7 +1163,7 @@ outputs:
               vars:
                 deploy_source_host: "DEPLOY_SOURCE_HOST"
                 deploy_target_host: "DEPLOY_TARGET_HOST"
-                ignore_unreachable: true
+                scale_ignore_unreachable: true
 
             - hosts: DEPLOY_TARGET_HOST
               name: Scaling