Extending support for Windows 7

[Doomster14]

Steam dropped support for Windows 7, 8 and 8.1. As a result, SteamCMD gives the following message when RimPy tries to download mods:

[----] Verifying installation...
[----] !!! Fatal Error: Steamcmd is no longer supported on your operating system version.
You may override this check by passing -overrideminos.
Steamcmd may not run properly and support for this override may be removed in the future.
Please update to a supported OS version for continued usage.

When I manually run SteamCMD, adding -overrideminos option, it works fine. Mods get downloaded/updated, but DateStamp file doesn't, of course.

Please, extend RimPy's support for Windows 7, 8 and 8.1, adding -overrideminos option when running SteamCMD on these operating systems. Don't add the option on Windows 10+, since it may be removed in the future, and therefore, SteamCMD may fail seeing an unknown option.

Tested on Windows 7 only, but supposedly applies to 8 and 8.1 too.