[gtk+] Fix a minor typo in translatable string

[Piotr Drąg <piotrdrag src gnome org>]

commit c88ec370376473ec6da82cf9e9c0cd5d211a98d3
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Mon Mar 23 17:35:41 2015 +0100

    Fix a minor typo in translatable string

 gtk/gtktexttag.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtktexttag.c b/gtk/gtktexttag.c
index f5f34f0..9296275 100644
--- a/gtk/gtktexttag.c
+++ b/gtk/gtktexttag.c
@@ -555,8 +555,8 @@ gtk_text_tag_class_init (GtkTextTagClass *klass)
   g_object_class_install_property (object_class,
                                    PROP_STRIKETHROUGH_RGBA,
                                    g_param_spec_boxed ("strikethrough-rgba",
-                                                       P_("Strike-through RGBA"),
-                                                       P_("Color of strike-through for this text"),
+                                                       P_("Strikethrough RGBA"),
+                                                       P_("Color of strikethrough for this text"),
                                                        GDK_TYPE_RGBA,
                                                        GTK_PARAM_READWRITE));