[gnome-shell-extensions] Update sass submodule

[Florian Müllner <fmuellner src gnome org>]

commit 11cad1f3b31dc67c40741b18712486589bb46d72
Author: Florian Müllner <fmuellner gnome org>
Date:   Thu Feb 21 21:55:36 2019 +0100

    Update sass submodule
    
    https://gitlab.gnome.org/GNOME/gnome-shell-extensions/merge_requests/56

 data/gnome-shell-sass | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/data/gnome-shell-sass b/data/gnome-shell-sass
index 985ca1f..055fefe 160000
--- a/data/gnome-shell-sass
+++ b/data/gnome-shell-sass
@@ -1 +1 @@
-Subproject commit 985ca1f7cb7dd3856c5a60189d284c8aad562592
+Subproject commit 055fefe597605cec6de6899667d4ff45f83a5857