[seahorse] common: Mark missing string for translation

[Piotr Drąg <piotrdrag src gnome org>]

commit eddc1c2bdbd867b69a12c80cfb96fc7b56927dcf
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Sun Jan 28 21:19:18 2018 +0100

    common: Mark missing string for translation

 common/add-keyserver-dialog.vala |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/common/add-keyserver-dialog.vala b/common/add-keyserver-dialog.vala
index f28abd3..f37bcb5 100644
--- a/common/add-keyserver-dialog.vala
+++ b/common/add-keyserver-dialog.vala
@@ -66,7 +66,7 @@ public class Seahorse.AddKeyserverDialog : Gtk.Dialog {
 
         // Buttons
         add_button(_("Cancel"), Gtk.ResponseType.CANCEL);
-        Gtk.Button save_button = (Gtk.Button) add_button(("Save"), Gtk.ResponseType.OK);
+        Gtk.Button save_button = (Gtk.Button) add_button(_("Save"), Gtk.ResponseType.OK);
         save_button.get_style_context().add_class("suggested-action");
 
         show();