gitfinder.py update

[koenbulcke]

Did some small mods to the script (extra parameters, catch keyboard interrupts), maybe you would want to reintegrate. I am not a Python specialist nor a full-time programmer, so the changes are rather quick 'n dirty (not optimized).

I still face a few issues with the Python finder script on Ubuntu 20.04:

if a make a list of for example two domains in a file (and I know both are having a .git exposed), the script only checks one domain and bails out (like it is not waiting on the other thread in the pool to come back?)
when the script exits, I get sometimes socket errors (timeouts?) like it is waiting on something that it wrongly requested