fix(handlers): honor DisableLoginBoost and DisableBoostTime fully (#187)

GetBoostTimeLimit and GetBoostRight now respect DisableBoostTime, and
UseKeepLoginBoost now respects DisableLoginBoost. Also fix a latent
zero-time.Time wraparound in GetBoostTimeLimit that caused the
"Boost Time" overlay to appear on fresh characters regardless of
config, since time.Time{}.Unix() cast to uint32 yields a large value
the client interprets as an active timestamp.

server/channelserver/handlers_event.go

@@ -195,6 +195,10 @@ func handleMsgMhfGetKeepLoginBoostStatus(s *Session, p mhfpacket.MHFPacket) {
 
 func handleMsgMhfUseKeepLoginBoost(s *Session, p mhfpacket.MHFPacket) {
 	pkt := p.(*mhfpacket.MsgMhfUseKeepLoginBoost)
+	if s.server.erupeConfig.GameplayOptions.DisableLoginBoost {
+		doAckBufSucceed(s, pkt.AckHandle, make([]byte, 5))
+		return
+	}
 	var expiration time.Time
 	bf := byteframe.NewByteFrame()
 	bf.WriteUint8(0)