Remove `environment_load` action chain. It wasn't used.

lib/vagrant/action/builtin.rb

@@ -96,7 +96,6 @@ module Vagrant
 
       # Other callbacks. There will be more of these in the future. For
       # now, these are limited to what are needed internally.
-      register :environment_load, Builder.new
       register(:before_action_run, Builder.new do
         use General::Validate
       end)

lib/vagrant/environment.rb

@@ -284,7 +284,6 @@ module Vagrant
         @loaded = true
         self.class.check_virtualbox!
         load_config!
-        actions.run(:environment_load)
       end
 
       self