added headless-client server-support
added headless-client server-support

Added server-support for headless clients. If this is not specified, no headless-client will be able to connect.
GameServerManagers/LinuxGSM,dgibbs64/linuxgsm,zunnu/linuxgsm,Maxximou5/linuxgameservers,zunnu/linuxgsm,dgibbs64/linuxgsm,Sodierlow/linuxgsm,Sodierlow/linuxgsm,GameServerManagers/LinuxGSM,Maxximou5/linuxgameservers