[glom] Fix the build.

[Murray Cumming <murrayc src gnome org>]

commit 541df42b9862c4c907eb54dc2b57d359ab016bf1
Author: Murray Cumming <murrayc murrayc com>
Date:   Mon Nov 7 14:35:02 2016 +0100

    Fix the build.

 glom/mode_data/db_adddel/db_adddel.cc |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/glom/mode_data/db_adddel/db_adddel.cc b/glom/mode_data/db_adddel/db_adddel.cc
index a1a5c0b..ec20cda 100644
--- a/glom/mode_data/db_adddel/db_adddel.cc
+++ b/glom/mode_data/db_adddel/db_adddel.cc
@@ -426,7 +426,7 @@ bool DbAddDel::select_item(const Gtk::TreeModel::iterator& iter, bool start_edit
   }
 
   if (!layout_item) {
-    return;
+    return false;
   }
 
   return select_item(iter, *layout_item, start_editing);