Use hasOwnProperty method to check if histogram is a time-series

lib/cartodb/models/dataview/histogram.js

@@ -42,7 +42,7 @@ module.exports = class Histogram {
     }
 
     _isDateHistogram (override = {}) {
-        return (this.options.aggregation !== undefined || override.aggregation !== undefined);
+        return (this.options.hasOwnProperty('aggregation') || override.hasOwnProperty('aggregation'));
     }
 
     getResult (psql, override, callback) {

lib/cartodb/models/dataview/histograms/numeric-histogram.js

@@ -64,7 +64,7 @@ const binsQueryTpl = ctx => `
                     ${ctx._maxBins}
                 )
             )
-        END AS __cdb_bins_number
+            END AS __cdb_bins_number
         FROM __cdb_basics, __cdb_iqrange, __cdb_filtered_source
         LIMIT 1
     )