Display "off-by-one" following iterator rework
test case:

```Nim
import ../src/arraymancer, sequtils

let a = toSeq(1..24).toTensor.reshape(6,4)

echo a
```

Result
```Nim
Tensor of shape 6x4 of type "int" on backend "Cpu"
        1|
|2      3       4       5|
|6      7       8       9|
|10     11      12      13|
|14     15      16      17|
|18     19      20      21|
|22     23      24
```

Introduced by: https://github.com/mratsim/Arraymancer/commit/829d8b16935f66bc773d93c91e5579b6a35fd502