Fix mod_suexec usage

The missing newline break apache configuration:

```
apache2: Syntax error on line 50 of /etc/apache2/apache2.conf: Syntax error on line 6 of /etc/apache2/sites-enabled/25-example.com-443.conf:6: <VirtualHost> was not closed.
```

Add the missing new line.

While here, alse remove the legacy (now unused) template and fix
indentation of the generated statement.

Author: smortex

manifests/vhost.pp

@@ -2713,7 +2713,7 @@
     concat::fragment { "${name}-suexec":
       target  => "${priority_real}${filename}.conf",
       order   => 290,
-      content => "SuexecUserGroup ${suexec_user_group}",
+      content => "  SuexecUserGroup ${suexec_user_group}\n",
     }
   }