Enable verify_host for synchronize

There is no need to have this disabled (seems to be by default). We
already have ensured our SSH hostkeys have been setup properly.

Change-Id: I5f0ffea13b4adb053c10d56728bcf02c13255513
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

playbooks/tox/post.yaml

@@ -19,4 +19,5 @@
         dest: "{{ zuul.executor.log_root }}/tox"
         mode: pull
         src: "{{ item.path }}/log/"
+        verify_host: true
       with_items: "{{ result.files }}"

playbooks/tox/tarball-post.yaml

@@ -5,6 +5,7 @@
         dest: "{{ zuul.executor.src_root }}/tarballs"
         mode: pull
         src: "src/{{ zuul.project.canonical_name }}/dist/{{ item }}"
+        verify_host: true
       with_items:
         - "*.tar.gz"
         - "*.whl"

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

@@ -3,4 +3,5 @@
     dest: "{{ zuul.executor.log_root }}"
     mode: pull
     src: "{{ zuul_work_dir }}/doc/build/html"
+    verify_host: true
   no_log: true

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

@@ -5,6 +5,7 @@
     rsync_opts:
       - "--ignore-missing-args"
     src: "{{ zuul_work_dir }}/{{ item }}"
+    verify_host: true
   with_items:
     - "*testr_results.html.gz"
     - "*testrepository.subunit.gz"