support transfer requestTemplate (#539)

sofa-tracer-plugins/sofa-tracer-spring-cloud-plugin/src/main/java/com/alipay/sofa/tracer/plugins/springcloud/instruments/feign/SofaTracerFeignClient.java

@@ -65,7 +65,7 @@ public Response execute(Request request, Request.Options options) {
             appendRequestSpanTagsAndInject(request, sofaTracerSpan, headers);
             // renew request with the headers that have been injected into the carrier
             request = Request.create(request.httpMethod(), request.url(), headers, request.body(),
-                request.charset());
+                request.charset(), request.requestTemplate());
             Response response = delegate.execute(request, options);
             // set result tags
             appendResponseSpanTags(response, sofaTracerSpan);