update the torrc file in snowflake/client

Otherwise it yields at a system with an already configured and running Tor client to

tfoerste@t44 ~/devel/go/src/snowflake/client $ tor -f torrc
Apr 19 18:55:47.450 [notice] Tor 0.4.7.0-alpha-dev (git-e7c407d927c80a94) running on Linux with Libevent 2.1.11-stable, OpenSSL 1.1.1k, Zlib 1.2.11, Liblzma 5.2.5, Libzstd 1.4.9 and Glibc 2.32 as libc.
Apr 19 18:55:47.450 [notice] Tor can't help you if you use it wrong! Learn how to be safe at https://www.torproject.org/download/download#warning
Apr 19 18:55:47.450 [notice] This version is not a stable Tor release. Expect more bugs than usual.
Apr 19 18:55:47.450 [notice] Read configuration file "/home/tfoerste/devel/go/src/snowflake/client/torrc".
Apr 19 18:55:47.451 [warn] Path for DataDirectory (datadir) is relative and will resolve to /home/tfoerste/devel/go/src/snowflake/client/datadir. Is this what you wanted?
Apr 19 18:55:47.453 [notice] Opening Socks listener on 127.0.0.1:9050
Apr 19 18:55:47.453 [warn] Could not bind to 127.0.0.1:9050: Address already in use. Is Tor already running?
Apr 19 18:55:47.453 [warn] Failed to parse/validate config: Failed to bind one of the listener ports.
Apr 19 18:55:47.453 [err] Reading config failed--see warnings above.