Quote numeric (octal) file modes.

In order for numeric file modes to still be properly interpreted as
octal modes in Puppet version 4 and later, they need to be specified
as strings, not as integers.  There was one instance where we had
missed that.  Fix it.

manifests/serial/login.pp

@@ -130,7 +130,7 @@ define console::serial::login::rhel_6(
 	file {
 	    "/etc/init/${svcname}.conf":
 		ensure => file,
-		owner => 'root', group => 'root', mode => 0444,
+		owner => 'root', group => 'root', mode => '0444',
 		content => inline_template(
 		    '<%= @lines.join("\n") + "\n" -%>'),
 		notify => Exec["console::serial::login::rhel_6::${name}"];