[gnome-boxes] meson: Drop the libhandy unstability acknownledgement

[Felipe Borges <felipeborges src gnome org>]

commit 09f4d025d5d9506587a46d0d5ff4aecfcc27a7c2
Author: Adrien Plazas <kekun plazas lapsote net>
Date:   Fri Sep 25 12:44:20 2020 +0200

    meson: Drop the libhandy unstability acknownledgement
    
    It's not required anymore since libhandy is stable.

 src/meson.build | 1 -
 1 file changed, 1 deletion(-)
---
diff --git a/src/meson.build b/src/meson.build
index 751ae2d1..a1638c9d 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -26,7 +26,6 @@ c_args = [
   '-DGETTEXT_PACKAGE="gnome-boxes"',
   '-DCACHEDIR="/var/cache/"',
   '-DG_LOG_DOMAIN="Boxes"',
-  '-DHANDY_USE_UNSTABLE_API=1',
 ]
 
 if get_option ('buildtype').contains ('debug')