[simple-scan] Update About menu item to new standard name

[Robert Ancell <rancell src gnome org>]

commit a230aef7dbb6846050fae91fff19277b8e7909ce
Author: Robert Ancell <robert ancell canonical com>
Date:   Fri Oct 5 09:46:50 2018 +1300

    Update About menu item to new standard name

 src/app-window.vala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/app-window.vala b/src/app-window.vala
index a62a5e1..2878e3a 100644
--- a/src/app-window.vala
+++ b/src/app-window.vala
@@ -1540,7 +1540,7 @@ public class AppWindow : Gtk.ApplicationWindow
         section.append (_("Preferences"), "app.preferences");
         section.append (_("Keyboard Shortcuts"), "win.show-help-overlay");
         section.append (_("Help"), "app.help");
-        section.append (_("About"), "app.about");
+        section.append (_("About Simple Scan"), "app.about");
         menu_button.set_menu_model (gear_menu);
 
         app.add_window (this);