socks5 does not appear to work at all

Socks5 when set via boto appears to be supported in the code. It is also listed as supported at


https://cloud.google.com/storage/docs/boto-gsutil

However when using socks5 type set in the .boto config. `gsutil` just hangs with process cpu usage at 99%.

Here is debug for an `ls` command.


Curiously rdns is set to true, despite a conditional check in `gslib/utils/boto_util.py` making it false if not http proxy. Thus for some reason perhaps it thinks the proxy is http, despite being set to socks5 in the .boto config.

Start by reproducing the hanging `gsutil ls` with a socks5 setting in the `.boto` configuration and inspect `gslib/utils/boto_util.py`, especially the conditional that handles proxy type and rdns. Done means the configured socks5 proxy is recognized correctly and the command no longer hangs; use the supplied debug output to compare behavior.

Written by the indexing model from the issue text.