Fix a few missing zuul_user usages

These got missed when we migrated everything else to zuuld.

Change-Id: Ia3dc9a1038622222e3bccd70e7dfe410b8bc89ca

playbooks/roles/zuul-executor/tasks/main.yaml

@@ -95,15 +95,15 @@
     content: '{{ nodepool_test_node_ssh_private_key_contents }}'
     dest: /var/lib/zuul/ssh/nodepool_id_rsa
     mode: 0400
-    owner: zuul
-    group: zuul
+    owner: '{{ zuul_user }}'
+    group: '{{ zuul_group }}'
 
 - name: Create Zuul Executor directories
   file:
     state: directory
     path: '{{ item }}'
-    owner: zuul
-    group: zuul
+    owner: '{{ zuul_user }}'
+    group: '{{ zuul_group }}'
   loop:
     - /var/lib/zuul/builds
     - /var/lib/zuul/git

playbooks/roles/zuul-merger/tasks/main.yaml

@@ -2,8 +2,8 @@
   file:
     state: directory
     path: '{{ item }}'
-    owner: zuul
-    group: zuul
+    owner: '{{ zuul_user }}'
+    group: '{{ zuul_group }}'
   loop:
     - /var/lib/zuul/git
 

playbooks/roles/zuul-scheduler/tasks/main.yaml

@@ -9,8 +9,8 @@
   copy:
     content: '{{ zuul_github_app_key }}'
     dest: /etc/zuul/github.key
-    owner: zuul
-    group: zuul
+    owner: '{{ zuul_user }}'
+    group: '{{ zuul_group }}'
     mode: 0600
 
 - name: Add openstack status backup