后台 报这个io/netty/channel/EventLoopGroup

ot cause

java.lang.NoClassDefFoundError: io/netty/channel/EventLoopGroup
    cn.jpush.api.push.PushClient.<init>(PushClient.java:103)
    cn.jpush.api.push.PushClient.<init>(PushClient.java:51)
    cn.jpush.api.JPushClient.<init>(JPushClient.java:57)
    Jpush.testSendPush(Jpush.java:32)
    JpushServlet.doGet(JpushServlet.java:26)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:620)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:727)