yum::cron::download: Silence debug messages on EL7

On EL7 '-d 0' doesn't silence all debug messages. Also increase
errorlevel by one.

yum/manifests/init.pp

@@ -36,9 +36,9 @@ class yum::cron::download {
 
     cron { "yum-cron-download":
         ensure  => present,
-        command => "yum -d 0 -e 0 -y --downloadonly update",
+        command => "yum -d 0 -e 1 -y --downloadonly update >/dev/null",
         user    => "root",
-        hour    => 3,
+        hour    => "3",
         minute  => fqdn_rand(60),
     }