minor change in RoutingTable::NthElementSortFromTarget

minor change in RoutingTable::NthElementSortFromTarget
the code above in gcc produces the following output
partial sorted at 0 is 0
nth elemented at 0, is 0
0 4 7 8 3 5 2 1 6 9 Partial
0 1 3 2 5 4 8 7 6 9 Nth_elem 

partial sorted at 1 is 5
nth elemented at 1, is 1
0 5 7 8 3 4 9 2 1 6 Partial
0 1 3 2 5 4 9 8 7 6 Nth_elem 

partial sorted at 2 is 7
nth elemented at 2, is 2
0 1 7 6 8 5 4 3 2 9 Partial
1 0 2 3 4 7 6 5 8 9 Nth_elem 

partial sorted at 3 is 7
nth elemented at 3, is 3
0 1 2 7 8 5 6 9 4 3 Partial
2 1 0 3 4 5 6 7 9 8 Nth_elem 

partial sorted at 4 is 5
nth elemented at 4, is 4
0 1 2 3 5 9 4 7 8 6 Partial
2 1 0 3 4 5 6 7 8 9 Nth_elem 

partial sorted at 5 is 8
nth elemented at 5, is 5
0 1 2 3 4 8 7 6 5 9 Partial
3 1 2 0 4 5 6 7 8 9 Nth_elem 

partial sorted at 6 is 9
nth elemented at 6, is 6
0 1 2 3 4 5 9 7 6 8 Partial
4 1 3 2 0 5 6 9 7 8 Nth_elem 

partial sorted at 7 is 9
nth elemented at 7, is 7
0 1 2 3 4 5 6 9 8 7 Partial
4 0 2 1 3 5 6 7 8 9 Nth_elem 

partial sorted at 8 is 9
nth elemented at 8, is 8
0 1 2 3 4 5 6 7 9 8 Partial
1 0 6 5 3 4 2 7 8 9 Nth_elem 

partial sorted at 9 is 9
nth elemented at 9, is 9
0 1 2 3 4 5 6 7 8 9 Partial
2 0 1 5 3 4 8 6 7 9 Nth_elem

which appears to me that  using two different elements as the target is not wrong