Fixed Windows warnings about struct.

Libs/PluginFramework/Testing/ConfigAdminTest/ctkConfigurationListenerTestSuite_p.h

@@ -31,7 +31,7 @@
 #include <ctkTestSuiteInterface.h>
 
 class ctkPluginContext;
-class ctkConfigurationAdmin;
+struct ctkConfigurationAdmin;
 class ctkConfigurationListenerTestSuite;
 
 class _ConfigurationListenerTest : public QObject,

Libs/PluginFramework/Testing/ConfigAdminTest/ctkConfigurationPluginTestSuite_p.h

@@ -32,7 +32,7 @@
 #include <ctkTestSuiteInterface.h>
 
 class ctkConfigurationPluginTestSuite;
-class ctkConfigurationAdmin;
+struct ctkConfigurationAdmin;
 
 class _ConfigurationPluginTest : public QObject, public ctkConfigurationPlugin
 {

Libs/PluginFramework/Testing/ConfigAdminTest/ctkManagedServiceFactoryTestSuite_p.h

@@ -31,7 +31,7 @@
 #include <ctkServiceReference.h>
 #include <ctkTestSuiteInterface.h>
 
-class ctkConfigurationAdmin;
+struct ctkConfigurationAdmin;
 class ctkManagedServiceFactoryTestSuite;
 
 class _ManagedServiceFactoryUpdateTest : public QObject,

Libs/PluginFramework/Testing/ConfigAdminTest/ctkManagedServiceTestSuite_p.h

@@ -32,7 +32,7 @@
 #include <ctkTestSuiteInterface.h>
 
 class ctkManagedServiceTestSuite;
-class ctkConfigurationAdmin;
+struct ctkConfigurationAdmin;
 
 class _ManagedServiceUpdateTest : public QObject, public ctkManagedService
 {