xwm: Redirect root window subwindows

xwayland no longer does this for us, we have to request it now
diff --git a/configure.ac b/configure.ac
index 5abf65f..7727930 100644
--- a/configure.ac
+++ b/configure.ac
@@ -92,7 +92,7 @@
 AM_CONDITIONAL(ENABLE_XWAYLAND, test x$enable_xwayland = xyes)
 AM_CONDITIONAL(ENABLE_XWAYLAND_TEST, test x$enable_xwayland = xyes -a x$enable_xwayland_test = xyes)
 if test x$enable_xwayland = xyes; then
-  PKG_CHECK_MODULES([XWAYLAND], xcb xcb-xfixes xcursor cairo-xcb)
+  PKG_CHECK_MODULES([XWAYLAND], xcb xcb-xfixes xcb-composite xcursor cairo-xcb)
   AC_DEFINE([BUILD_XWAYLAND], [1], [Build the X server launcher])
 
   AC_ARG_WITH(xserver-path, AS_HELP_STRING([--with-xserver-path=PATH],