[rhythmbox] don't crash when re-enabling library monitoring (bug #672198)

[Jonathan Matthew <jmatthew src gnome org>]

commit 39ab91a26b3e028f9afaa6ccf2f22a8ede3a820a
Author: Jonathan Matthew <jonathan d14n org>
Date:   Wed May 16 07:44:21 2012 +1000

    don't crash when re-enabling library monitoring (bug #672198)

 rhythmdb/rhythmdb.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/rhythmdb/rhythmdb.c b/rhythmdb/rhythmdb.c
index 8d937c6..5a49a2a 100644
--- a/rhythmdb/rhythmdb.c
+++ b/rhythmdb/rhythmdb.c
@@ -4697,6 +4697,7 @@ rhythmdb_sync_library_location (RhythmDB *db)
 		rhythmdb_stop_monitoring (db);
 
 		g_strfreev (db->priv->library_locations);
+		db->priv->library_locations = NULL;
 	}
 
 	if (g_settings_get_boolean (db->priv->settings, "monitor-library")) {