Why ClanArena ends after round 6 despite server setting to infinite?

I want to play the Clan Arena with bots indefinitely. So before launching the server I set "frag limit" to "infinite" and "time limit" to "infinite".
However, the game ends after one side won 6 rounds.
How do I set it to infinite rounds?

Easy. Open console(press ~ or SHIFT+ESC), type there "leadlimit 0" or "leadlimit 9999" in game, so the game won't end after 6 rounds (because leadlimit is set 6 by default)

Thanks.
Why not make leadlimit a configurable parameter in setting screen...