[gimp] app: update a comment for translators.

[Jehan Pagès <jehanp src gnome org>]

commit 2707cff8909a70724b7cdb09831e2d463a3c1295
Author: Jehan <jehan girinstud io>
Date:   Sat Dec 14 10:26:55 2013 +1300

    app: update a comment for translators.
    
    The current comment is technical and not meant for translators, but it
    ends up in po file. Move it where it won't be extracted and add a real
    comment for translators. Ideally this string should not be extracted by
    xgettext, but it won't verify domains.

 app/gui/gui.c |   15 ++++++++++-----
 1 files changed, 10 insertions(+), 5 deletions(-)
---
diff --git a/app/gui/gui.c b/app/gui/gui.c
index 24cebdc..7d9983d 100644
--- a/app/gui/gui.c
+++ b/app/gui/gui.c
@@ -199,13 +199,18 @@ gui_init (Gimp     *gimp,
 
   the_gui_gimp = gimp;
 
-  /* Normally this should have been taken care of during command line
-   * parsing as a post-parse hook of gtk_get_option_group(), using the
-   * system locales.
-   * But user config may have overriden the language, therefore we must
-   * check the widget directions again.
+  /* TRANSLATORS: there is no need to translate this in GIMP. This uses
+   * "gtk20" domain as a special trick to determine language direction,
+   * but xgettext extracts it anyway mistakenly into GIMP po files.
+   * Leave an empty string as translation. It does not matter.
    */
   if (g_strcmp0 (dgettext ("gtk20", "default:LTR"), "default:RTL") == 0)
+    /* Normally this should have been taken care of during command line
+     * parsing as a post-parse hook of gtk_get_option_group(), using the
+     * system locales.
+     * But user config may have overriden the language, therefore we must
+     * check the widget directions again.
+     */
     gtk_widget_set_default_direction (GTK_TEXT_DIR_RTL);
   else
     gtk_widget_set_default_direction (GTK_TEXT_DIR_LTR);