Update to HttpServerResponse close method removal

Author: vietj

src/test/java/io/vertx/httpproxy/ProxyClientKeepAliveTest.java

@@ -238,7 +238,7 @@ private void testBackendCloseResponse(TestContext ctx, boolean chunked) {
       }
       resp.write("part");
       closeFuture.thenAccept(v -> {
-        resp.close();
+        req.connection().close();
       });
     });
     startProxy(backend);

src/test/java/io/vertx/httpproxy/ProxyRequestTest.java

@@ -175,7 +175,7 @@ private void testCloseBackendResponse(TestContext ctx, boolean chunked) {
       }
       resp.write("part");
       cont.thenAccept(v -> {
-        resp.close();
+        req.connection().close();
       });
     });
     backendClient = vertx.createHttpClient(new HttpClientOptions(clientOptions));