fix labels overlapping in bar chart x-axis

pdb-plotting/src/main/java/org/lucares/pdb/plot/api/BarChartAggregatorForIntervals.java

@@ -101,7 +101,7 @@ public class BarChartAggregatorForIntervals implements CustomAggregator, Indexed
         if (maxLabels >= numberOfBuckets) {
             return true;
         } else {
-            return index % (int) Math.ceil(numberOfBuckets / maxLabels) == 0;
+            return index % (int) Math.ceil(numberOfBuckets / (double) maxLabels) == 0;
         }
     }