异步获得用户时，空指针

at com.easemob.chat.EMPresenceHandler.processRosterPresence(Unknown Source)
10-11 20:03:24.380 29553-30519/com.dg.app W/System.err:     at com.easemob.chat.EMChatManager.processRosterPresence(Unknown Source)
10-11 20:03:24.380 29553-30519/com.dg.app W/System.err:     at com.easemob.chat.EMChatManager.processOfflinePresenceMessages(Unknown Source)
10-11 20:03:24.380 29553-30519/com.dg.app W/System.err:     at com.easemob.chat.EMChatManager.onAppInited(Unknown Source)
10-11 20:03:24.380 29553-30519/com.dg.app W/System.err:     at com.easemob.chat.EMChat.setAppInited(Unknown Source)
10-11 20:03:24.390 29553-30519/com.dg.app W/System.err:     at com.easemob.applib.controller.HXSDKHelper.notifyForRecevingEvents(HXSDKHelper.java:663)
10-11 20:03:24.390 29553-30519/com.dg.app W/System.err:     at com.dg.app.ui.MainActivity$2.onSuccess(MainActivity.java:283)
10-11 20:03:24.400 29553-30519/com.dg.app W/System.err:     at com.dg.app.ui.MainActivity$2.onSuccess(MainActivity.java:228)
10-11 20:03:24.400 29553-30519/com.dg.app W/System.err:     at com.easemob.applib.controller.HXSDKHelper$4.run(HXSDKHelper.java:562)