[mutter] clutter/build: Don't pass --prototypes to glib-genmarshal

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit cbbd3e366a173310340963c1a3f2535292851937
Author: Jonas Ådahl <jadahl gmail com>
Date:   Sun Jan 20 11:44:32 2019 +0100

    clutter/build: Don't pass --prototypes to glib-genmarshal
    
    This causes compilation warnings and the prototypes are declared in the
    header file already.

 clutter/clutter/meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/clutter/clutter/meson.build b/clutter/clutter/meson.build
index af5755062..321792a70 100644
--- a/clutter/clutter/meson.build
+++ b/clutter/clutter/meson.build
@@ -491,7 +491,7 @@ clutter_marshal = gnome.genmarshal('clutter-marshal',
   prefix: '_clutter_marshal',
   sources: 'clutter-marshal.list',
   valist_marshallers: true,
-  extra_args: ['--prototypes', '--quiet'],
+  extra_args: ['--quiet'],
   install_dir: clutter_clutter_includedir,
   install_header: true,
 )