Hide getcap error message in torsocks
Since torsocks 2.2.0, torsocks calls getcap on the file to be executed. For filesystems which don't support file capabilities, this results in an error message being printed to stderr, e.g.:
Failed to get capabilities of file /usr/bin/git' (Operation not supported)`
This message is not really useful to the user. Maybe it should be hidden.
This affects Tails: https://labs.riseup.net/code/issues/12091