switch backup_upstream from undef to []

Tim Meusel · Tim Meusel · commit 555b7e0e1fb0 · 2015-01-22T14:07:37.000+01:00
diff --git a/manifests/params.pp b/manifests/params.pp
@@ -34,7 +34,7 @@
   $listen_address                   = '*'
   $default_webserver                = 'httpd'
   $disable_ssl                      = undef
-  $backup_upstream                  = undef
+  $backup_upstream                  = []
 
   # Only used when environments == directory
   $environmentpath                  = '$confdir/environments'
