Dont enable Wi-Fi if it's not toggleable in flight mode

Dont enable Wi-Fi if it's not toggleable in flight mode
by restoring the return which was removed by
e78c187905

Change-Id: I8ca5a3e9b3f36f148f08ce97b8a2b854bf7de21c

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

@@ -108,6 +108,7 @@ public class WifiEnabler implements CompoundButton.OnCheckedChangeListener  {
             Toast.makeText(mContext, R.string.wifi_in_airplane_mode, Toast.LENGTH_SHORT).show();
             // Reset switch to off. No infinite check/listenenr loop.
             buttonView.setChecked(false);
+            return;
         }
 
         // Disable tethering if enabling Wifi