Stop writing sensitive information about multiplayer matches in mainlog.html

[Stan]

Currently, every network message received is logged in mainlog.html. This is very convenient for developers, but also for people that want to cheat. This is why by default it should be turned off for releases.

This includes observer messages, ally messages, and global messages. This also includes every command sent by the players, such as attack, move, build etc.

Of course, anyone recompiling the game can still change it but it's only a first layer of security.

Thread: ​https://wildfiregames.com/forum/topic/107064-mainloghtml-reveals-too-much-sensitive-information/