Update gc_private_network_bridges.rb

lib/vagrant-lxc/action/gc_private_network_bridges.rb

@@ -35,7 +35,7 @@ module Vagrant
 
             if ! driver.bridge_is_in_use?(bridge)
               env[:ui].info I18n.t("vagrant_lxc.messages.remove_bridge", name: bridge)
-              # TODO: Output that bridge is being removed
+              if bridge_name != "lxcbr0"
                  driver.remove_bridge(bridge)
               end
             end
@@ -44,3 +44,4 @@ module Vagrant
       end
     end
   end
+end