Prevents calling an empty filter
Fix loader position
Merge branch 'develop' of github.com:CartoDB/cartodb20 into develop

* 'develop' of github.com:CartoDB/cartodb20:
  changed share controller to check if there is private tables related to the visualization using the new vis collection and not the plain object
  changed vis to accept get related_tables and generate the correct collection
  changed share private tables dialog + specs, now using collection
  privacy selector with new related_tables collection applied
  cdb, as always, no updated