🐞 fix: stateListener 改为 let

Author: ccnnde

index.js

@@ -21,7 +21,7 @@ import { NativeModules, NativeEventEmitter } from 'react-native';
 
 const { RNSimpleOpenvpn } = NativeModules;
 const localEventEmitter = new NativeEventEmitter(RNSimpleOpenvpn);
-const stateListener = null;
+let stateListener = null;
 
 export const addVpnStateListener = (callback) => {
   stateListener = localEventEmitter.addListener('stateChanged', (e) => callback(e));