PD: fix small inconsistence, use forwared declaration

src/Mod/PartDesign/Gui/TaskPipeParameters.cpp

@@ -215,7 +215,7 @@ void TaskPipeParameters::onSelectionChanged(const Gui::SelectionChanges& msg)
                     ui->spineBaseEdit->clear();
                 }
             }
-            else if (stateHandler->getSelectionMode() == StateHandlerTaskPipe::refSpine) {
+            else if (stateHandler->getSelectionMode() == StateHandlerTaskPipe::SelectionModes::refSpine) {
                 ui->listWidgetReferences->clear();
 
                 App::Document* document = App::GetApplication().getDocument(msg.pDocName);

src/Mod/PartDesign/Gui/TaskPipeParameters.h

@@ -27,7 +27,6 @@
 #include <Gui/TaskView/TaskView.h>
 #include <Gui/Selection.h>
 #include <Gui/TaskView/TaskDialog.h>
-#include <Gui/Widgets.h>
 
 #include "TaskSketchBasedParameters.h"
 #include "ViewProviderPipe.h"
@@ -39,6 +38,7 @@ class Property;
 }
 
 namespace Gui {
+class ButtonGroup;
 class ViewProvider;
 }