Thanks daniel34, that worked .

This could be expanded with a "game version" dropdown below mods/password if the game goes minecraft-style and has extremely huge mods that can take weeks/months to update, but right now pretty much everyone updates right away it seems.

When searching for a server i noticed that instead of saying "this server is running a higher version, please update your game" it simply does not show up in the game list at all.
Might even be a bug since the game does list the server version.

Bonus: if people already updated their client ...