未选择城数据默认加载数据为空，会报错

[duhualong]

Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'void com.baronzhang.android.weather.contract.DrawerContract$Presenter.subscribe()' on a null object reference
at com.baronzhang.android.weather.view.fragment.DrawerMenuFragment.onCreateView(DrawerMenuFragment.java:120)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:2239)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1332)
at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1574)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1641)
at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:2959)
at android.support.v4.app.FragmentController.dispatchActivityCreated(FragmentController.java:201)
at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:550)
at android.support.v7.app.AppCompatActivity.onStart(AppCompatActivity.java:177)
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1249)
at android.app.Activity.performStart(Activity.java:6762)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2651)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2749) 
at android.app.ActivityThread.-wrap12(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1498) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:160) 
at android.app.ActivityThread.main(ActivityThread.java:6200) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:874) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:764)