Sanitize jinja2 variables

tasks/main.yml

@@ -106,7 +106,7 @@
     authorized_key: user=sshsvn
                     key={{sshsvnpubkey.stdout}} {{inventory_hostname}}
     delegate_to: '{{item}}'
-    with_items: '{{ groups.svnserver }}'
+    with_items: '{{ groups.svnserver|default([]) }}'
     tags: 'ResetSVNUser'
 
   - name: 'Subversion | Copy Svnserve Auth File'