Explicitly disable HTTP cache in ClientApi

Change the ClientApi to disable the HTTP cache, while the API responses
shouldn't be cached it seems they were, sometimes, which broke some use
cases (e.g. poll the status of a scan).

Related to zaproxy/zaproxy#4462 - ZAP Jenkins plugin does not obtain
latest spider status

Author: thc202

CHANGES.md

@@ -4,6 +4,9 @@ Summary of the changes done in each version.
 
 ## 1.6.0 (Not yet released)
 
+### Changes
+
+ - Explicitly disable HTTP caching, to always obtain a fresh response from ZAP.
 
 ## 1.5.0 (2017-11-30)
 

subprojects/zap-clientapi/src/main/java/org/zaproxy/clientapi/core/ClientApi.java

@@ -351,6 +351,7 @@ private Document callApiDom(
 
     private InputStream getConnectionInputStream(HttpRequest request) throws IOException {
         HttpURLConnection uc = (HttpURLConnection) request.getRequestUri().openConnection(proxy);
+        uc.setUseCaches(false);
         for (Entry<String, String> header : request.getHeaders().entrySet()) {
             uc.setRequestProperty(header.getKey(), header.getValue());
         }