[SeaBIOS] no cert for git.seabios.org

[Michael Tokarev]

FWIW, git.seabios.org can't be contacted anymore:

$ git remote -v
upstream	https://git.seabios.org/seabios.git (fetch)
upstream	https://git.seabios.org/seabios.git (push)
$ git remote update upstream
Fetching upstream
fatal: unable to access 'https://git.seabios.org/seabios.git/': gnutls_handshake() failed: The server name sent was not recognized
error: could not fetch upstream

Firefox shows SSL_ERROR_UNRECOGNIZED_NAME_ALERT error when trying
https://git.seabios.org/

Thanks,

/mjt