DoS vulnerability (invalid player id spam)

there has been DoS attack going around spamming HEADER_CG_CHARACTER_SELECT with an invalid character id causing the db to overload and crash,

in the db syslog you will find many [PLAYER_LOAD] Load from PlayerDB pid[0] entries

to fix this:

goto input_login.cpp

add above

this fix will make sure the player gets disconnected upon choosing an invalid character, making it harder to spam and making rate limits effective again

Thanks go to:

CYN3 for being my mental support

PR1ME for getting attacked

please be fair and give credits when you repost this.