fix urls in download_example_data.sh

download_example_data.sh

-wget https://people.eecs.berkeley.edu/~bmild/nerf/tiny_nerf_data.npz
+wget http://cseweb.ucsd.edu/~viscomp/projects/LF/papers/ECCV20/nerf/tiny_nerf_data.npz
 mkdir -p data
 cd data
-wget https://people.eecs.berkeley.edu/~bmild/nerf/nerf_example_data.zip
+wget http://cseweb.ucsd.edu/~viscomp/projects/LF/papers/ECCV20/nerf/nerf_example_data.zip
 unzip nerf_example_data.zip
 cd ..