[gthumb] rename: clarified string context for translators

[Paolo Bacchilega <paobac src gnome org>]

commit 4c67aff4dc7cdcff2d0af882aaa46993b0c03683
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Mon Dec 28 15:50:09 2015 +0100

    rename: clarified string context for translators

 extensions/rename_series/gth-template-selector.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/extensions/rename_series/gth-template-selector.c 
b/extensions/rename_series/gth-template-selector.c
index a5a51c6..3f997c7 100644
--- a/extensions/rename_series/gth-template-selector.c
+++ b/extensions/rename_series/gth-template-selector.c
@@ -242,6 +242,7 @@ gth_template_selector_construct (GthTemplateSelector *self,
        }
 
        gtk_list_store_append (list_store, &iter);
+       /* Translators: this is an option for the format -> Format: Custom */
        gtk_list_store_set (list_store, &iter,
                            DATE_FORMAT_FORMAT_COLUMN, "",
                            DATE_FORMAT_NAME_COLUMN, _("Custom"),