Servient top-level resource always returns an empty layer instead of available resources

[FadySalama]

Currently, the top-level resource provided by the servient is returning an empty array instead of the resources to access all available Things inside of the servient as it used to do. Please refer to http://plugfest.thingweb.io:8083/ which should contain the three resources http://plugfest.thingweb.io:8083/testthing, http://plugfest.thingweb.io:8083/counter and http://plugfest.thingweb.io:8083/smart-coffee-machine. I was able to reproduce the same bug locally.

[relu91]

Thank you Fady! I noticed a while ago but I forgot to report. It is due to the changes of the HTTP binding. However, we should deprecate that way of listing TDs and comply with the Discovery spec.

Related to #786 .