[gnome-settings-daemon] media-keys: Fix compile-time warning

[Bastien Nocera <hadess src gnome org>]

commit d498252c3f4d9173e14b9f3482b325cda40800d7
Author: Bastien Nocera <hadess hadess net>
Date:   Sat Sep 17 19:48:27 2011 +0100

    media-keys: Fix compile-time warning

 plugins/media-keys/gsd-media-keys-manager.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/plugins/media-keys/gsd-media-keys-manager.c b/plugins/media-keys/gsd-media-keys-manager.c
index b71c3af..c2ddf96 100644
--- a/plugins/media-keys/gsd-media-keys-manager.c
+++ b/plugins/media-keys/gsd-media-keys-manager.c
@@ -28,6 +28,7 @@
 #include <unistd.h>
 #include <string.h>
 #include <errno.h>
+#include <math.h>
 
 #include <locale.h>