fix logic

now also the case that one switches from add mode directly to remove mode is correctly handled
also remove doubled code that is already executed

src/Mod/PartDesign/Gui/TaskDressUpParameters.cpp

@@ -132,9 +132,7 @@ void TaskDressUpParameters::onButtonRefAdd(bool checked)
         Gui::Selection().addSelectionGate(new ReferenceSelection(this->getBase(), allowEdges, allowFaces, false));
         DressUpView->highlightReferences(true);
     } else {
-        clearButtons(none); 
         exitSelectionMode();
-        showObject();
         DressUpView->highlightReferences(false);
     }
 }
@@ -150,9 +148,7 @@ void TaskDressUpParameters::onButtonRefRemove(const bool checked)
         DressUpView->highlightReferences(true);
     }
     else {
-        clearButtons(none);
         exitSelectionMode();
-        showObject();
         DressUpView->highlightReferences(false);
     }
 }