修复支付配置信息不能重复设置BUG

weixin-java-mp/src/main/java/me/chanjar/weixin/mp/api/impl/WxMpPayServiceImpl.java

@@ -73,17 +73,13 @@ public class WxMpPayServiceImpl implements WxMpPayService {
     "REFUND_SOURCE_UNSETTLED_FUNDS"};
   protected final Logger log = LoggerFactory.getLogger(this.getClass());
   private WxMpService wxMpService;
-  private WxMpConfigStorage config = null;
 
   public WxMpPayServiceImpl(WxMpService wxMpService) {
     this.wxMpService = wxMpService;
   }
   
   private WxMpConfigStorage getConfig(){
-    if(config == null){
-      this.config = wxMpService.getWxMpConfigStorage();
-    }
-    return this.config;
+      return  wxMpService.getWxMpConfigStorage();
   }
 
   @Override