Rewrite ghost var

Something wrong occurred in last merge:
* https://github.com/bassosimone/rivoluzionedigitale/commit/4295394a9fcb398d05f5468434ff50ddf487bc7a here I removed MAYBE_EMPTY_TOKEN for error;
* https://github.com/bassosimone/rivoluzionedigitale/commit/d8a19db5edd5b9ca472b946b36298f71523ba238 in fact in the following commit I restore it.

But when you merge all commits, that var disappeared.