Fix detection of next build number

If many multiple jobs are starting at the same time, it is not safe to
query next build number and then launch the job. Instead, pick up the
build number from the POST response directly.

src/main/java/org/jenkinsci/plugins/ParameterizedRemoteTrigger/RemoteBuildConfiguration.java

@@ -525,25 +525,17 @@ public boolean perform(AbstractBuild build, Launcher launcher, BuildListener lis
         String queryUrlString = this.buildGetUrl(jobName, securityToken);
         queryUrlString += "/api/json/";
 
-        //listener.getLogger().println("Getting ID of next job to build. URL: " + queryUrlString);
-        JSONObject queryResponseObject = sendHTTPCall(queryUrlString, "GET", build, listener);
-        if (queryResponseObject == null ) {
-            //This should not happen as this page should return a JSON object
-            this.failBuild(new Exception("Got a blank response from Remote Jenkins Server [" + remoteServerURL + "], cannot continue."), listener);
-        }
-
-        int nextBuildNumber = queryResponseObject.getInt("nextBuildNumber");
-        listener.getLogger().println("This job is build #[" + Integer.toString(nextBuildNumber) + "] on the remote server.");
-
         if (this.getOverrideAuth()) {
             listener.getLogger().println(
                     "Using job-level defined credentails in place of those from remote Jenkins config ["
                             + this.getRemoteJenkinsName() + "]");
         }
 
         listener.getLogger().println("Triggering remote job now.");
-        sendHTTPCall(triggerUrlString, "POST", build, listener);
-
+        JSONObject queryResponseObject = sendHTTPCall(triggerUrlString, "POST", build, listener);
+        int nextBuildNumber = queryResponseObject.getInt("nextBuildNumber");
+        listener.getLogger().println("This job is build #[" + Integer.toString(nextBuildNumber) + "] on the remote server.");
+
         //Have to form the string ourselves, as we might not get a response from non-parameterized builds
         String jobURL = remoteServerURL + "/job/" + this.encodeValue(job) + "/";