[simple-scan] Make string translatable

[Robert Ancell <rancell src gnome org>]

commit b5159a79dde76bffd3ec381df199fbcc09c90e2b
Author: Robert Ancell <robert ancell canonical com>
Date:   Mon May 29 17:02:45 2017 +1200

    Make string translatable

 src/app-window.vala |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/app-window.vala b/src/app-window.vala
index 4ef5b22..dbe87af 100644
--- a/src/app-window.vala
+++ b/src/app-window.vala
@@ -509,7 +509,7 @@ public class AppWindow : Gtk.ApplicationWindow
         var format = uri_to_format (uri);
 
         var cancellable = new Cancellable ();
-        var progress_bar =  new CancellableProgressBar ("Saving", cancellable);
+        var progress_bar =  new CancellableProgressBar (_("Saving"), cancellable);
         action_bar.pack_end (progress_bar);
         progress_bar.visible = true;
         try