This resolves two set of warnings pointed by compiler
-Wimplicit-function-declaration and -Wint-conversion, where the later
one can result with segfault caused by invalid cast from int to pointer.
Fixes: 665a709b522a ("webext: Exchange fd over webkit messages")
#include <gdk/gdk.h>
#include <gdk/gdkkeysyms.h>
#include <gdk/gdkx.h>
+#include <gio/gunixfdlist.h>
#include <glib/gstdio.h>
#include <gtk/gtk.h>
#include <gtk/gtkx.h>
#include <stdlib.h>
#include <gio/gio.h>
+#include <gio/gunixfdlist.h>
#include <webkit2/webkit-web-extension.h>
#include <webkitdom/webkitdom.h>
#include <webkitdom/WebKitDOMDOMWindowUnstable.h>