support custom bb private keys

ServerState.cc

@@ -1,5 +1,7 @@
 #include "ServerState.hh"
 
+#include <string.h>
+
 #include <memory>
 
 #include "SendCommands.hh"
@@ -14,6 +16,8 @@ ServerState::ServerState() : run_dns_server(true),
     allow_unregistered_users(false),
     run_shell_behavior(RunShellBehavior::Default), next_lobby_id(1),
     pre_lobby_event(0) {
+  memset(&this->default_key_file, 0, sizeof(this->default_key_file));
+
   this->main_menu.emplace_back(MAIN_MENU_GO_TO_LOBBY, u"Go to lobby",
       u"Join the lobby.", 0);
   this->main_menu.emplace_back(MAIN_MENU_INFORMATION, u"Information",