[gnome-settings-daemon] media-keys: Update gvc to fix a crash setting a headset

[Bastien Nocera <hadess src gnome org>]

commit 1ee74eab6e2d839f17f6f8767f05410bb5663ef0
Author: Bastien Nocera <hadess hadess net>
Date:   Sun Apr 17 22:32:14 2016 +0200

    media-keys: Update gvc to fix a crash setting a headset

 plugins/media-keys/gvc |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/plugins/media-keys/gvc b/plugins/media-keys/gvc
index 0a50079..25bf3ed 160000
--- a/plugins/media-keys/gvc
+++ b/plugins/media-keys/gvc
@@ -1 +1 @@
-Subproject commit 0a500795bde6254e14eda9be03904b7015a84146
+Subproject commit 25bf3ed75fa604fa73e8b25241119a993fc659d6