Remove remaining ineffective parameter for plumgrid plugin

The plumgrid plugin is no longer supported since Wallaby[1]. This
change removes the remaining deprecated parameter to clean up all
related implementations.

[1] f7c40f7056

Change-Id: Id43ffae22cb5795246c9fe8d7682b2cca49ed50e

manifests/config.pp

@@ -92,9 +92,6 @@
 # [*api_config*]
 #   (optional) Manage configuration of api-paste.ini
 #
-# [*plugin_plumgrid_config*]
-#   (optional) Manage configuration of plugins/plumgrid/plumgrid.ini
-#
 # [*plugin_midonet_config*]
 #   (optional) Manage configuration of plugins/midonet/midonet.ini
 #
@@ -126,16 +123,11 @@ class neutron::config (
   $plugin_nvp_config             = {},
   # DEPRECATED PARAMETERS
   $api_config                    = undef,
-  $plugin_plumgrid_config        = undef,
   $plugin_midonet_config         = undef,
 ) {
 
   include neutron::deps
 
-  if $plugin_plumgrid_config != undef {
-    warning('The plugin_plumgrid_config parameter was deprecated and has no effect')
-  }
-
   if $api_config != undef {
     warning('The neutron::config::api_config parameter has been deprecated and \
 will be removed in a future release. Use the api_paste_ini parameter instead.')

releasenotes/notes/cleanup-plumgrid-6ae80b90642507c2.yaml

@@ -0,0 +1,4 @@
+---
+upgrade:
+  - |
+    The ``neutron::config::plugin_plumgrid_config`` parameter has been removed.