configure xwayland surfaces without monitors

For wine clients often configurex11() is called before mapnotify() and
therefore c->mon is NULL. configurex11 just returns early in that case,
letting these clients stay in the wrong size. For example only the top
left part of winecfg and wine uninstaller is drawn, or confirmation
dialogs like when closing wine notepad are too big. Fix this by
configuring their surfaces like before 88d386b.

dwl.c

@@ -2844,8 +2844,12 @@ configurex11(struct wl_listener *listener, void *data)
 {
 	Client *c = wl_container_of(listener, c, configure);
 	struct wlr_xwayland_surface_configure_event *event = data;
-	if (!c->mon)
+	/* TODO: figure out if there is another way to do this */
+	if (!c->mon) {
+		wlr_xwayland_surface_configure(c->surface.xwayland,
+				event->x, event->y, event->width, event->height);
 		return;
+	}
 	if (c->isfloating || client_is_unmanaged(c))
 		resize(c, (struct wlr_box){.x = event->x, .y = event->y,
 				.width = event->width, .height = event->height}, 0);