Fix un-selecting user cert for VPN.

Bug was introduced in https://codereview.chromium.org/421113002 .

BUG=

Review URL: https://codereview.chromium.org/552353002

Cr-Commit-Position: refs/heads/master@{#293948}

chrome/browser/chromeos/options/vpn_config_view.cc

@@ -454,8 +454,8 @@ void VPNConfigView::SetUserCertProperties(
     base::DictionaryValue* properties) const {
   if (!HaveUserCerts()) {
     // No certificate selected or not required.
-    chromeos::client_cert::SetEmptyShillProperties(
-        chromeos::client_cert::CONFIG_TYPE_EAP, properties);
+    chromeos::client_cert::SetEmptyShillProperties(client_cert_type,
+                                                   properties);
   } else {
     // Certificates are listed in the order they appear in the model.
     int index = user_cert_combobox_ ? user_cert_combobox_->selected_index() : 0;