Broken link in "Reduce and Scan"

[Dietmar Suoch]

The "Reduce and Scan" chapter tries to link to "NVIDIA's Mark Harris on Optimizing Parallel Reduction in CUDA" but uses

`https://moderngpu.github.io/http|//developer.download.nvidia.com/assets/cuda/files/reduction.pdf`

instead of

`http://developer.download.nvidia.com/assets/cuda/files/reduction.pdf`