Switch VirtualBox DNS proxying and host resolver off

While those helped with some issues, the proxying is substantially
broken and the smoke tests wouldn't pass.

Vagrantfile

@@ -10,8 +10,8 @@ Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
 
   config.vm.network "private_network", ip: vm_ip
   config.vm.provider :virtualbox do |vb|
-    vb.customize ["modifyvm", :id, "--natdnshostresolver1", "on"]
-    vb.customize ["modifyvm", :id, "--natdnsproxy1", "on"]
+    vb.customize ["modifyvm", :id, "--natdnshostresolver1", "off"]
+    vb.customize ["modifyvm", :id, "--natdnsproxy1", "off"]
   end
 
   config.vm.synced_folder ".", "/vagrant", disabled: true

test/Vagrantfile

@@ -34,8 +34,8 @@ end
 Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
 
   config.vm.provider :virtualbox do |vb|
-    vb.customize ["modifyvm", :id, "--natdnshostresolver1", "on"]
-    vb.customize ["modifyvm", :id, "--natdnsproxy1", "on"]
+    vb.customize ["modifyvm", :id, "--natdnshostresolver1", "off"]
+    vb.customize ["modifyvm", :id, "--natdnsproxy1", "off"]
   end
 
   (1..n_machines).each do |i|