Fix "Sketch → In Workplane" not updating the UI immediately.

src/graphicswin.cpp

@@ -1227,6 +1227,8 @@ void GraphicsWindow::MenuRequest(Command id) {
             if(SS.GW.gs.n == 1 && SS.GW.gs.workplanes == 1) {
                 // A user-selected workplane
                 g->activeWorkplane = SS.GW.gs.entity[0];
+                SS.GW.EnsureValidActives();
+                SS.ScheduleShowTW();
             } else if(g->type == Group::Type::DRAWING_WORKPLANE) {
                 // The group's default workplane
                 g->activeWorkplane = g->h.entity(0);