Fix checked in. Note that the jsp extension is only converted to htm, if the value passed to Page#setRedirect(String) starts with a '/' character. The reason is that you might want to redirect to a real JSP page somewhere in the application. This leaves a backdoor open for such a scenario.
However the common use case is to use the other setRedirect method: Page#setRedirect(Class) which will work out of the box since it uses getContext().getPagePath(Class) underneath. Calling getPagePath always starts with a '/' character.