当对apk进行travel时Armser类抛出空指针错误

操作机型：三星I9300
cafe版本：3.1
相关log
java.lang.NullPointerException
at com.baidu.cafe.remote.Armser.getTopActivity(Armser.java:1239)
at com.baidu.cafe.local.traveler.APPTraveler.travel(APPTraveler.java:116)
at com.baidu.cafe.local.LocalLib.travel(LocalLib.java:2335)
at com.baidu.cafe.local.LocalLib.travel(LocalLib.java:2343)
at com.baidu.cafe.test.CafeTraveler.test_travel(CafeTraveler.java:39)
at java.lang.reflect.Method.invokeNative(Native Method)
at android.test.InstrumentationTestCase.runMethod(InstrumentationTestCase.java:214)
at android.test.InstrumentationTestCase.runTest(InstrumentationTestCase.java:199)
at android.test.ActivityInstrumentationTestCase2.runTest(ActivityInstrumentationTestCase2.java:192)
at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:191)
at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:176)
at android.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:554)
at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1738)

Reproduce APK travel on a Samsung I9300 with Cafe 3.1, then inspect Armser.java:1239, where the NullPointerException occurs from APPTraveler.java:116. Follow the call path through LocalLib.java:2335 and CafeTraveler.java:39; done means travel no longer fails with this exception.

Written by the indexing model from the issue text.