paginator-box: Register window before setting parent
Prevents newly created widgets from reusing parent's window. Fixes a regression from e6a47749 Fixes Librem5/libhandy#165 Signed-off-by: Alexander Mikhaylenko <alexm@gnome.org>
Prevents newly created widgets from reusing parent's window. Fixes a regression from e6a47749 Fixes Librem5/libhandy#165 Signed-off-by: Alexander Mikhaylenko <alexm@gnome.org>