information disclosure: operating system and platform

By running a relay you are disclosing your operating system and platform.

examples:

platform Tor 0.2.1.30 on Linux x86_64
platform Tor 0.2.1.29 (!r8e9b25e6c7a2e70c) on Very recent version of Windows [major=6,minor=1]  [workstation] {terminal services, single user}
platform Tor 0.2.1.30 on Linux i686
platform Tor 0.2.1.30 on Very recent version of Windows [major=6,minor=1]  [workstation] {personal} {terminal services, single user}

To minimize info. discl. the version string should not include the operating system and platform by default.