Fixed NullPointerException in PicassoProvider

src/de/danoeh/antennapod/asynctask/PicassoProvider.java

@@ -127,7 +127,11 @@ public class PicassoProvider {
                     mmr.setDataSource(uri.getPath());
                     byte[] data = mmr.getEmbeddedPicture();
                     mmr.release();
+                    if (data != null) {
                         return new Response(new ByteArrayInputStream(data), true, data.length);
+                    } else {
+                        return null;
+                    }
                 }
             }