Our wget_verify function uses wget to download a file and then check
the file's hash. If wget fails, i.e. because of a 404 or other HTTP
or network error, we exited setup without displaying any output because
normally there are no errors and -q keeps the setup output clean.

Wrapping wget with our hide_output function, and dropping -q, captures
wget's output and shows it and exits setup just if wget fails.

see #1297