[polari] pasteManager: Fix promisifying class method

[Florian Müllner <fmuellner src gnome org>]

commit 2d853baad2eec6b29c642ed654692cf78a447ff2
Author: Juan R. García Blanco <juanrgar gmail com>
Date:   Mon Jun 21 11:58:46 2021 +0200

    pasteManager: Fix promisifying class method
    
    Methods new_from_stream_async and new_from_stream_finish are class
    methods in GdkPixbuf.Pixbuf. They therefore don't show up on the
    prototype, but on GdkPixbuf.Pixbuf directly.
    
    https://gitlab.gnome.org/GNOME/polari/-/issues/179

 src/pasteManager.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/pasteManager.js b/src/pasteManager.js
index b44b20fa..06b91ef8 100644
--- a/src/pasteManager.js
+++ b/src/pasteManager.js
@@ -18,7 +18,7 @@ Gio._promisify(Gio._LocalFilePrototype,
 Gio._promisify(Gio._LocalFilePrototype,
     'query_info_async', 'query_info_finish');
 Gio._promisify(Gio._LocalFilePrototype, 'read_async', 'read_finish');
-Gio._promisify(GdkPixbuf.Pixbuf.prototype,
+Gio._promisify(GdkPixbuf.Pixbuf,
     'new_from_stream_async', 'new_from_stream_finish');
 
 const DndTargetType = {