Revert change 85b43ea as it brings unexpected behavior if Plugins/Modules contain old versions of CakePHP

#1578

Author: nook24

src/Lib/PluginManager.php

@@ -89,9 +89,12 @@ private function addAllPlugins() {
             );
             $this->application->addPlugin($moduleName);
 
-            if (is_file(PLUGIN . $moduleName . DS . 'vendor/autoload.php')) {
-                require PLUGIN . $moduleName . DS . 'vendor/autoload.php';
-            }
+            // https://github.com/it-novum/openITCOCKPIT/pull/1578
+            // This leads to issues when Plugins/Modules have older version of CakePHP (to run Tests for example)
+            // Issues like 'Unknown method "selectQuery" called on App\\Model\\Table\\AgentchecksTable'
+            //if (is_file(PLUGIN . $moduleName . DS . 'vendor/autoload.php')) {
+            //    require PLUGIN . $moduleName . DS . 'vendor/autoload.php';
+            //}
 
             $pluginAssociationsFile = PLUGIN . $moduleName . DS . 'config' . DS . 'associations.php';
             if (file_exists($pluginAssociationsFile)) {