[recipes] Add a translator comment

[Matthias Clasen <matthiasc src gnome org>]

commit 5e0f0cf712045e808c385ceb0964b8c8b6ee03f5
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Jul 15 08:38:05 2017 -0400

    Add a translator comment

 src/gr-window.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/src/gr-window.c b/src/gr-window.c
index ca54f18..51f79c4 100644
--- a/src/gr-window.c
+++ b/src/gr-window.c
@@ -1601,6 +1601,7 @@ play_tada_sound (GtkWindow *win)
         ca_context_play (c, 0,
                          CA_PROP_MEDIA_ROLE, "alert",
                          CA_PROP_MEDIA_FILENAME, path,
+                         /* Translators: there is a thin space before the !, on purpose */
                          CA_PROP_MEDIA_NAME, _("GNOME turns 20 !"),
                          NULL);
 #endif