Fix cron setup logic

If $site_base_url and $conf are unset, catalog compilation fails
because the cron resource tries to access $conf['cron_key'] and $conf
is not a hash. If $conf is a hash but does not contain the 'cron_key'
key, a cron is created with the command

 wget -O /dev/null -q -t 1 false/cron.php?cron_key=

which is not sensible and will result in failed crons. It only makes
sense to create this cron if $site_base_url and $conf are set, so this
patch checks that they are set before creating the cron resource.

Change-Id: Ib40350e7b3c5c6261812d00a20decd8692acb4bb

manifests/init.pp

@@ -282,14 +282,16 @@ class drupal (
 
   # setup cron job
 
-  cron { $site_name:
-    name    => "${site_name}.cron",
-    command => "wget -O /dev/null -q -t 1 ${$site_base_url}/cron.php?cron_key=${$conf['cron_key']}",
-    user    => root,
-    minute  => '*/5',
-    require => [
-      Exec["sitedeploy-${site_name}"],
-      ]
+  if $site_base_url != false and is_hash($conf) {
+    cron { $site_name:
+      name    => "${site_name}.cron",
+      command => "wget -O /dev/null -q -t 1 ${$site_base_url}/cron.php?cron_key=${$conf['cron_key']}",
+      user    => root,
+      minute  => '*/5',
+      require => [
+        Exec["sitedeploy-${site_name}"],
+        ]
+    }
   }
 
 }