desktop-shell: launch clients in their own process group.

Client applications shouldn't be in the same process group as
the display server.

Signed-off-by: Derek Foreman <derekf@osg.samsung.com>
Reviewed-by: Quentin Glidic <sardemff7+git@sardemff7.net>

clients/desktop-shell.c

@@ -212,6 +212,10 @@ panel_launcher_activate(struct panel_launcher *widget)
 		return;
 
 	argv = widget->argv.data;
+
+	if (setsid() == -1)
+		exit(EXIT_FAILURE);
+
 	if (execve(argv[0], argv, widget->envp.data) < 0) {
 		fprintf(stderr, "execl '%s' failed: %m\n", argv[0]);
 		exit(1);