[gnome-contacts] Fix passing null to a non-nullable function parameter

[Philip Withnall <pwithnall src gnome org>]

commit 2037d8f1a38adde26216e71aca1e25367011b181
Author: Philip Withnall <philip tecnocode co uk>
Date:   Sun Aug 4 09:55:48 2013 +0200

    Fix passing null to a non-nullable function parameter

 src/contacts-app.vala |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/src/contacts-app.vala b/src/contacts-app.vala
index 016b14f..0617e3b 100644
--- a/src/contacts-app.vala
+++ b/src/contacts-app.vala
@@ -75,7 +75,7 @@ public class Contacts.App : Gtk.Application {
     if (contacts_pane.on_edit_mode) {
       contacts_pane.set_edit_mode (false);
 
-      contact_name.set_text (null);
+      contact_name.set_text ("");
       done_button.hide ();
     }
 
@@ -362,7 +362,7 @@ public class Contacts.App : Gtk.Application {
       });
 
     done_button.clicked.connect (() => {
-        contact_name.set_text (null);
+        contact_name.set_text ("");
         done_button.hide ();
         edit_button.show ();
         contacts_pane.set_edit_mode (false);
@@ -532,7 +532,7 @@ public class Contacts.App : Gtk.Application {
 
   private void delete_contact (Contact contact) {
     /* unsetting edit-mode */
-    contact_name.set_text (null);
+    contact_name.set_text ("");
     done_button.hide ();
     contacts_pane.set_edit_mode (false);