Merge pull request #1448 from uggedal/fix-unqualified-reference-to-nfs-no-hostonly-network-error

Fix wrong reference to Errors::NFSNoHostonlyNetwork

plugins/providers/virtualbox/action/prepare_nfs_settings.rb

@@ -13,7 +13,7 @@ module VagrantPlugins
           env[:nfs_host_ip]    = read_host_ip(env[:machine])
           env[:nfs_machine_ip] = read_machine_ip(env[:machine])
 
-          raise Errors::NFSNoHostonlyNetwork if !env[:nfs_machine_ip]
+          raise Vagrant::Errors::NFSNoHostonlyNetwork if !env[:nfs_machine_ip]
         end
 
         # Returns the IP address of the first host only network adapter