Use real data on new-dashboard datasets view

Solves #1453 
An empty table (0 rows) will not be render that info, won't it? [Here](https://github.com/CartoDB/cartodb/commit/ff4ad785e53e6565cc911df1a60c4acd562378f9#diff-0e3d19e8245c224c0075f5ea1824b691R26)