do not draw diagonal lines in ParallelRequestsAggregator

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

@@ -19,7 +19,7 @@ public class ParallelRequestsAggregator implements CustomAggregator {
 
 	private final Path tmpDir;
 
-	private final int[] increments;
+	private final short[] increments;
 
 	private final long fromEpochMilli;
 
@@ -33,7 +33,7 @@ public class ParallelRequestsAggregator implements CustomAggregator {
 		}
 
 		final int milliseconds = (int) (toEpochMilli - fromEpochMilli);
-		increments = new int[milliseconds];
+		increments = new short[milliseconds];
 	}
 
 	@Override
@@ -61,9 +61,10 @@ public class ParallelRequestsAggregator implements CustomAggregator {
 			final StringBuilder data = new StringBuilder();
 
 			int value = 0;
-			for (int i = 0; i < increments.length; i++) {
+			for (int i = 0; i < increments.length - 1; i++) {
 				final int increment = increments[i];
-				if (increment != 0) {
+				final int nextIncrement = increments[i + 1];
+				if (increment != 0 || nextIncrement != 0) {
 					value += increment;
 					data.append(String.format("%.3f", (fromEpochMilli + i) / 1000.0));
 					data.append(separator);