small fix in merge sort

Author: lor6

algorithms-sorting/src/main/java/com/baeldung/algorithms/mergesort/MergeSort.java

@@ -34,7 +34,7 @@ public static void merge(int[] a, int[] l, int[] r, int left, int right) {
 
         while (i < left && j < right) {
 
-            if (l[i] < r[j])
+            if (l[i] <= r[j])
                 a[k++] = l[i++];
             else
                 a[k++] = r[j++];