Wifi state reset when disconnected

https://review.source.android.com/19086

Change-Id: Ie7367f2240b94569fed3120244f1cb268bb09206

src/com/android/settings/wifi/WifiSettings.java

@@ -615,6 +615,8 @@ public class WifiSettings extends SettingsPreferenceFragment
                 break;
         }
 
+        mLastInfo = null;
+        mLastState = null;
         mScanner.pause();
     }