[geary: 6/6] Replace client call to Gtk.show_uri() with show_uri_on_window().

[Michael Gratton <mjog src gnome org>]

commit 6c6737d2adb4c93fb2c4ce0caa2843cc23649792
Author: Michael James Gratton <mike vee net>
Date:   Sat Dec 2 01:03:51 2017 +1100

    Replace client call to Gtk.show_uri() with show_uri_on_window().
    
    Former is deprecated, latter works better with Flatpak.
    
    * src/client/application/geary-application.vala: Use show_uri_on_window.

 src/client/application/geary-application.vala |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)
---
diff --git a/src/client/application/geary-application.vala b/src/client/application/geary-application.vala
index 683f649..27712f9 100644
--- a/src/client/application/geary-application.vala
+++ b/src/client/application/geary-application.vala
@@ -342,9 +342,8 @@ public class GearyApplication : Gtk.Application {
      * Displays a URI on the current active window, if any.
      */
     public void show_uri(string uri) throws Error {
-        Gtk.Window? window = get_active_window();
-        bool success = Gtk.show_uri(
-            window != null ? window.get_screen() : null, uri, Gdk.CURRENT_TIME
+        bool success = Gtk.show_uri_on_window(
+            get_active_window(), uri, Gdk.CURRENT_TIME
         );
         if (!success) {
             throw new IOError.FAILED("gtk_show_uri() returned false");