Recommended args for masif-search are not correct

[mpdunne]

Should be ./compute_descriptors.sh -l lists/testing.txt.

[mpdunne]

Even with this changed compute_descriptors.sh command does nothing: the items from the input list never get used (eval_list).

[pablogainza]

It is weird because I have been using it and they do get used:

if len(eval_list) > 0 and ppi_pair_id not in eval_list: 
    continue

I added a small explanation for compute_descriptors.sh