Correct indentation of docker_puppet_apply.sh run

The backport of Icf4a64ed76635e39bbb34c3a088c55e1f14fddca had an
indentation error which caused the command to be
['/docker_puppet_apply.sh'] instead of '/docker_puppet_apply.sh'

This caused an error when paunch logged the command it would run.

Making the paunch logging more robust would have made this easier to
debug, as would capturing /var/log/tripleo-config in our CI jobs.

Change-Id: I80734ccc842d5be01555ee5a863d0de9a8101d33
Closes-Bug: #1743754

docker/services/haproxy.yaml

@@ -162,14 +162,14 @@ outputs:
             privileged: true
             command: # '/docker_puppet_apply.sh "STEP" "TAGS" "CONFIG" "DEBUG"'
               list_concat:
-              - - - '/docker_puppet_apply.sh'
-                - '1'
-                - 'tripleo::firewall::rule'
-                - {get_attr: [HAProxyBase, role_data, step_config]}
-              - if:
-                 - puppet_debug_enabled
-                 - - '--debug --verbose'
-                 - - ''
+                - - '/docker_puppet_apply.sh'
+                  - '1'
+                  - 'tripleo::firewall::rule'
+                  - {get_attr: [HAProxyBase, role_data, step_config]}
+                - if:
+                   - puppet_debug_enabled
+                   - - '--debug --verbose'
+                   - - ''
             volumes:
               list_concat:
                 - {get_attr: [ContainersCommon, docker_puppet_apply_volumes]}