Alpha7中，频道收消息会出现NPE

[qfys521]

java.lang.NullPointerException: Cannot invoke "io.github.kloping.qqbot.entities.
qqpd.Guild.setMember(io.github.kloping.qqbot.entities.qqpd.Member)" because the
return value of "io.github.kloping.qqbot.impl.BaseMemberUpdateEvent.getGuild()"
is null
        at io.github.kloping.qqbot.impl.BaseMemberUpdateEvent.<init>(BaseMemberU
pdateEvent.java:21)
        at io.github.kloping.qqbot.impl.registers.MemberEventRegisters.handle(Me
mberEventRegisters.java:43)
        at io.github.kloping.qqbot.network.Events.onEvent(Events.java:78)
        at io.github.kloping.qqbot.network.Events.lambda$onReceive$0(Events.java
:47)
        at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executo
rs.java:539)
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoo
lExecutor.java:1136)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPo
olExecutor.java:635)
        at java.base/java.lang.Thread.run(Thread.java:833)