Do not use --ignore-missing-args for rsync

rsync --ignore-missing-args is only supported with rsync 3.1. CentOS 7
uses rsync 3.0 and fails.

We ignore missing remote files, so remove the argument and let the role
ignore an error if the files do not exist.

Update fetch-tox-output to use failed_when as well. We really want the
role not to fail (failed_when) instead of showing a failure and then the
playbook ignore it (ignore_errors).

Change-Id: I24bfb5519acccd7fd36b4839bb598436b4c8f01c

roles/fetch-stestr-output/tasks/main.yaml

@@ -12,8 +12,6 @@
   synchronize:
     dest: "{{ zuul.executor.log_root }}"
     mode: pull
-    rsync_opts:
-      - "--ignore-missing-args"
     src: "{{ zuul_work_dir }}/{{ item }}"
     verify_host: true
   with_items:
@@ -21,3 +19,5 @@
     - "*testrepository.subunit.gz"
   when:
     - stestr_stat.stat.exists
+  # some tox runs may not create test-results
+  failed_when: false

roles/fetch-testr-output/tasks/main.yaml

@@ -12,8 +12,6 @@
   synchronize:
     dest: "{{ zuul.executor.log_root }}"
     mode: pull
-    rsync_opts:
-      - "--ignore-missing-args"
     src: "{{ zuul_work_dir }}/{{ item }}"
     verify_host: true
   with_items:
@@ -21,3 +19,5 @@
     - "*testrepository.subunit.gz"
   when:
     - testrepository_stat.stat.exists
+  # some tox runs may not create test-results
+  failed_when: false

roles/fetch-tox-output/tasks/main.yaml

@@ -40,4 +40,4 @@
   with_items: "{{ envlist }}"
   # some tox runs may not create a virtualenv and thus have
   # no ./tox/env directory
-  ignore_errors: yes
+  failed_when: false