[gnome-shell] portalHelper: Require GTK 3.0

[Carlos Garnacho <carlosg src gnome org>]

commit 4871845d0146b30dfd8dad93dd86d1557e40dca4
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Jan 31 09:23:48 2020 +0100

    portalHelper: Require GTK 3.0
    
    When multiple versions of a typelib are available, GI will pick the
    highest one unless an explicit version is requested. So as GTK 4.0
    is becoming a thing, it's time to do that.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/970

 js/portalHelper/main.js | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/js/portalHelper/main.js b/js/portalHelper/main.js
index dc062a279b..b0e568dacb 100644
--- a/js/portalHelper/main.js
+++ b/js/portalHelper/main.js
@@ -1,4 +1,6 @@
 /* exported main */
+imports.gi.versions.Gtk = '3.0';
+
 const Format = imports.format;
 const Gettext = imports.gettext;
 const { Gio, GLib, GObject, Gtk, Pango, Soup, WebKit2: WebKit } = imports.gi;