🎨 #4067 恢复默认 HTTP 客户端兼容性，避免非 Starter 手动集成时因默认引入 HttpClient5 导致的问题

weixin-java-pay/src/main/java/com/github/binarywang/wxpay/service/impl/WxPayServiceImpl.java

@@ -2,11 +2,11 @@ package com.github.binarywang.wxpay.service.impl;
 
 /**
  * <pre>
- * 微信支付接口请求实现类，默认使用Apache HttpClient 5实现
+ * 微信支付接口请求实现类，默认使用 Apache HttpClient 4 实现.
  * Created by Binary Wang on 2017-7-8.
  * </pre>
  *
  * @author <a href="https://github.com/binarywang">Binary Wang</a>
  */
-public class WxPayServiceImpl extends WxPayServiceHttpComponentsImpl {
+public class WxPayServiceImpl extends WxPayServiceApacheHttpImpl {
 }

weixin-java-pay/src/test/java/com/github/binarywang/wxpay/service/impl/BaseWxPayServiceImplTest.java

@@ -59,6 +59,11 @@ public class BaseWxPayServiceImplTest {
   @Inject
   private WxPayService payService;
 
+  @Test
+  public void testDefaultImplUsesApacheHttpClient() {
+    assertThat(new WxPayServiceImpl()).isInstanceOf(WxPayServiceApacheHttpImpl.class);
+  }
+
   /**
    * Test method for {@link WxPayService#unifiedOrder(WxPayUnifiedOrderRequest)}.
    *