[gnome-music/wip/carlosg/tracker3] albumartcache: Protect for elements returning 0 results

[Carlos Garnacho <carlosg src gnome org>]

commit 8e0837251795c7e72451e85965f50c1dab30c677
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sun Jun 28 18:54:41 2020 +0200

    albumartcache: Protect for elements returning 0 results
    
    Now that the grl-tracker3-source is handled properly all through,
    this seems to fail with some albums here, where remote album art
    look ups fail.

 gnomemusic/albumartcache.py | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/gnomemusic/albumartcache.py b/gnomemusic/albumartcache.py
index 6c388711..9ad5e05b 100644
--- a/gnomemusic/albumartcache.py
+++ b/gnomemusic/albumartcache.py
@@ -672,6 +672,10 @@ class RemoteArt(GObject.GObject):
             self.emit('unavailable')
             return
 
+        if count == 0:
+            self.emit('unavailable')
+            return
+
         thumb_uri = item.get_thumbnail()
 
         if (thumb_uri is None