[gnome-builder/document-manager] GbDevhelpDocument: implement get_modified().

[Christian Hergert <chergert src gnome org>]

commit c1442bbb459aa35bf5aabb37d8f91b77a6596347
Author: Christian Hergert <christian hergert me>
Date:   Tue Dec 9 16:44:41 2014 -0800

    GbDevhelpDocument: implement get_modified().

 src/devhelp/gb-devhelp-document.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/src/devhelp/gb-devhelp-document.c b/src/devhelp/gb-devhelp-document.c
index a8f75d1..9808bcb 100644
--- a/src/devhelp/gb-devhelp-document.c
+++ b/src/devhelp/gb-devhelp-document.c
@@ -153,4 +153,5 @@ static void
 gb_document_init (GbDocumentInterface *iface)
 {
   iface->get_title = gb_devhelp_document_get_title;
+  iface->get_modified = gb_devhelp_document_get_modified;
 }