Brad Fitzpatrick 6fbc9b3a98 control/controlclient: cache Windows version
To atone for 1d7f9d5b4a59b3e, the revert of 4224b3f73110f6f.

At least it's fast again, even if it's shelling out to cmd.exe (once now).

Updates #1478

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-15 21:40:32 -07:00
..