[rhythmbox] magnatune: fix crash opening preferences dialog (bug #672084)

[Jonathan Matthew <jmatthew src gnome org>]

commit 7b344c68e25ec6ac61b4eef15659316d7859ed91
Author: Ole Laursen <olau hardworking dk>
Date:   Thu Mar 15 07:35:48 2012 +1000

    magnatune: fix crash opening preferences dialog (bug #672084)

 plugins/magnatune/magnatune.py |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/plugins/magnatune/magnatune.py b/plugins/magnatune/magnatune.py
index ce2aeb3..e88f0e2 100644
--- a/plugins/magnatune/magnatune.py
+++ b/plugins/magnatune/magnatune.py
@@ -214,8 +214,8 @@ class MagnatuneConfig(GObject.GObject, PeasGtk.Configurable):
 			builder.get_object("stream_account_radio").set_active(account_type == "stream")
 			builder.get_object("download_account_radio").set_active(account_type == "download")
 
-			builder.get_object("username_entry").set_text(username)
-			builder.get_object("password_entry").set_text(password)
+			builder.get_object("username_entry").set_text(username or "")
+			builder.get_object("password_entry").set_text(password or "")
 
 			update_sensitivity(account_type)