purge env_file if unmanaged

The previous version of this code left the file lying around if the
env_vars values were emptied. Proper practice should make sure that
file is garbage-collected if unmanaged.

manifests/daemon.pp

@@ -214,15 +214,19 @@
     'none': {}
   }
 
-  if $init_style == 'none' and $install_method == 'package' {
+  if $init_style == 'none' and $install_method == 'package' and !$options.empty {
     $env_vars_merged = $env_vars + {
       'ARGS' => $options,
     }
   } else {
     $env_vars_merged = $env_vars
   }
 
-  unless $env_vars_merged.empty {
+  if $env_vars_merged.empty {
+    file { "${env_file_path}/${name}":
+      ensure => absent,
+    }
+  } else {
     file { "${env_file_path}/${name}":
       mode    => '0644',
       owner   => 'root',