Fix for #1561 catching errors
Merge branch 'master' into 1561-json_visualizations_controller_fails_for_unlinked_tables
Merge branch 'master' into 1561-json_visualizations_controller_fails_for_unlinked_tables
Merge branch 'master' into 1561-json_visualizations_controller_fails_for_unlinked_tables
Merge pull request #1562 from CartoDB/1561-json_visualizations_controller_fails_for_unlinked_tables

Fix for #1561 catching errors