[polari] thumbnailer: Specify WebKit2 version

[Florian Müllner <fmuellner src gnome org>]

commit 8357e686b91b9126b25cb50b2a89992ced09837a
Author: Florian Müllner <fmuellner gnome org>
Date:   Thu Jun 24 22:56:37 2021 +0200

    thumbnailer: Specify WebKit2 version
    
    Soup-3.0 is shaping up, and there is now a WebKit2-4.1 version that
    uses it instead of the current 2.4.
    
    https://gitlab.gnome.org/GNOME/polari/-/merge_requests/196

 src/thumbnailer.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/thumbnailer.js b/src/thumbnailer.js
index 64c1fd48..6e0c8626 100644
--- a/src/thumbnailer.js
+++ b/src/thumbnailer.js
@@ -4,7 +4,7 @@ import Gio from 'gi://Gio';
 import GLib from 'gi://GLib';
 import GObject from 'gi://GObject';
 import Gtk from 'gi://Gtk?version=3.0';
-import WebKit2 from 'gi://WebKit2';
+import WebKit2 from 'gi://WebKit2?version=4.0';
 
 Gio._promisify(WebKit2.WebView.prototype, 'get_snapshot', 'get_snapshot_finish');
 Gio._promisify(WebKit2.WebView.prototype, 'run_javascript', 'run_javascript_finish');