[rygel] renderer-gst: Add missing default

[Jens Georg <jensgeorg src gnome org>]

commit 4d2219759b5c1d062b0abd37f1b548bf1cfc2cd5
Author: Jens Georg <mail jensge org>
Date:   Sun Aug 2 11:37:21 2020 +0200

    renderer-gst: Add missing default
    
    Fixes a warning produced by recent vala

 src/librygel-renderer-gst/rygel-playbin-player.vala | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/src/librygel-renderer-gst/rygel-playbin-player.vala 
b/src/librygel-renderer-gst/rygel-playbin-player.vala
index a65bd605..b7993d0e 100644
--- a/src/librygel-renderer-gst/rygel-playbin-player.vala
+++ b/src/librygel-renderer-gst/rygel-playbin-player.vala
@@ -588,6 +588,8 @@ public class Rygel.PlaybinPlayer : GLib.Object, Rygel.MediaPlayer {
 
             this.playback_state = "STOPPED";
 
+            break;
+        default:
             break;
         }
     }