providers/docker: always copy the host VM Vagrantfile

plugins/providers/docker/hostmachine/Vagrantfile

@@ -7,7 +7,4 @@ Vagrant.configure("2") do |config|
     v.check_guest_additions = false
     v.functional_vboxsf     = false
   end
-
-  # Don't sync this directory
-  config.vm.synced_folder ".", "/vagrant", disabled: true
 end

plugins/providers/docker/provider.rb

@@ -60,12 +60,10 @@ module VagrantPlugins
           default_path = File.expand_path("../hostmachine/Vagrantfile", __FILE__)
           vf_path      = @machine.env.data_dir.join("docker-host", "Vagrantfile")
           begin
-            if !vf_path.file?
             @machine.env.lock("docker-provider-hostvm") do
               vf_path.dirname.mkpath
               FileUtils.cp(default_path, vf_path)
             end
-            end
           rescue Vagrant::Errors::EnvironmentLockedError
             # Lock contention, just retry
             retry