[folks] eds: Do not pass empty vCard attribute groups to EDS

[Philip Withnall <pwithnall src gnome org>]

commit 01ad839337bbb2db66c3bcbd9097b24fd2565a37
Author: Philip Withnall <philip withnall collabora co uk>
Date:   Tue Jun 16 14:42:08 2015 +0100

    eds: Do not pass empty vCard attribute groups to EDS
    
    Older version of EDS do not treat the following two calls as equivalent:
       new VCardAttribute (null, "X-HELLO")
       new VCardAttribute ("", "X-HELLO")
    when they should be. Work around that by always passing null anyway.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=751044

 backends/eds/lib/edsf-persona-store.vala |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/backends/eds/lib/edsf-persona-store.vala b/backends/eds/lib/edsf-persona-store.vala
index 451fcd4..aa3f05f 100644
--- a/backends/eds/lib/edsf-persona-store.vala
+++ b/backends/eds/lib/edsf-persona-store.vala
@@ -1787,7 +1787,7 @@ public class Edsf.PersonaStore : Folks.PersonaStore
       if (prev_attr != null)
           vcard.remove_attribute (prev_attr);
 
-      E.VCardAttribute new_attr = new E.VCardAttribute ("", name);
+      E.VCardAttribute new_attr = new E.VCardAttribute (null, name);
       new_attr.add_value (details.value);
 
       vcard.add_attribute (new_attr);
@@ -2273,7 +2273,7 @@ public class Edsf.PersonaStore : Folks.PersonaStore
       if (prev_attr != null)
         contact.remove_attributes (null, group_ids_str);
 
-      E.VCardAttribute new_attr = new E.VCardAttribute ("", group_ids_str);
+      E.VCardAttribute new_attr = new E.VCardAttribute (null, group_ids_str);
       foreach (var group in system_groups)
         {
           if (group == null || group == "")