[rhythmbox] artsearch: don't try to look at tags if there aren't any

[Jonathan Matthew <jmatthew src gnome org>]

commit cf4c0b59d93677dd77c6bd376262299182fdbcf4
Author: Jonathan Matthew <jonathan d14n org>
Date:   Thu Dec 25 08:15:31 2014 +1000

    artsearch: don't try to look at tags if there aren't any

 plugins/artsearch/embedded.py |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/plugins/artsearch/embedded.py b/plugins/artsearch/embedded.py
index 136d584..206df54 100644
--- a/plugins/artsearch/embedded.py
+++ b/plugins/artsearch/embedded.py
@@ -34,6 +34,9 @@ class EmbeddedSearch(object):
 
        def discovered_cb(self, discoverer, info, error):
                tags = info.get_tags()
+               if tags is None:
+                       return
+
                for tagname in ('image', 'preview-image'):
                        (found, sample) = tags.get_sample(tagname)
                        if not found: