Add back addresses.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Shared/ProviderConfigurationKeys.swift

@@ -0,0 +1,13 @@
+//
+//  ProviderConfigurationKeys.swift
+//  WireGuard
+//
+//  Created by Jeroen Leenarts on 12-08-18.
+//  Copyright © 2018 WireGuard. All rights reserved.
+//
+
+import Foundation
+
+enum PCKeys: String {
+    case title, tunnelIdentifier, endpoints, dns, addresses, mtu, settings
+}