Do not add stopwatch if already added

Author: Nyholm

CHANGELOG.md

@@ -6,6 +6,7 @@
 ### Added
 
 - Support for BatchClient
+- The stopwatch plugin in included by default when using profiling. 
 
 ### Changed
 

DependencyInjection/HttplugExtension.php

@@ -218,8 +218,10 @@ private function configureClient(ContainerBuilder $container, $name, array $argu
         $pluginClientOptions = [];
 
         if ($profiling) {
-            // Add the stopwatch plugin
-            array_unshift($arguments['plugins'], 'httplug.plugin.stopwatch');
+            if (!in_array('httplug.plugin.stopwatch', $arguments['plugins'])) {
+                // Add the stopwatch plugin
+                array_unshift($arguments['plugins'], 'httplug.plugin.stopwatch');
+            }
 
             // Tell the plugin journal what plugins we used
             $container