Remove broken method from flux.md documentation

This doesn't actually work. You should instead read path from `state` provided by `Router.run` in a callback, and fire your own custom action if you'd like.

Author: gaearon

docs/guides/flux.md

@@ -65,10 +65,6 @@ To avoid this, you can do one of three things:
      var router;
 
      module.exports = {
-      getCurrentPath() {
-        return router.getCurrentPath();
-      },
-
       makePath(to, params, query) {
         return router.makePath(to, params, query);
       },