[tracker] tracker-needle: Fix build with up-to-date gtk+ vapi

[Carlos Garnacho <carlosg src gnome org>]

commit 53007652ce1ed3cf350ec042b310606e0115377a
Author: Carlos Garnacho <carlosg gnome org>
Date:   Tue Feb 28 21:03:49 2017 +0100

    tracker-needle: Fix build with up-to-date gtk+ vapi
    
    The GtkListStore remove method now takes a ref TreeIter.

 src/tracker-needle/tracker-tags-view.vala |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/tracker-needle/tracker-tags-view.vala b/src/tracker-needle/tracker-tags-view.vala
index 40e9f19..d0309c8 100644
--- a/src/tracker-needle/tracker-tags-view.vala
+++ b/src/tracker-needle/tracker-tags-view.vala
@@ -514,7 +514,7 @@ public class TrackerTagsView : Box {
                        yield connection.update_async (query, Priority.DEFAULT, td.cancellable);
 
                        debug ("Tag removed");
-                       store.remove (td.iter);
+                       store.remove (ref td.iter);
                } catch (GLib.Error e) {
                        warning ("Could not run Sparql update query: %s", e.message);
                        show_error_dialog (_("Could not remove tag"), e);