PD: [skip ci] fix regression caused by e0d07257b7

In the accept() method the view provider of the edited object must be made visible if it's valid as otherwise it can happen that the view is empty.

See https://forum.freecadweb.org/viewtopic.php?f=13&t=55915

src/Mod/PartDesign/Gui/TaskFilletParameters.cpp

@@ -281,6 +281,10 @@ TaskDlgFilletParameters::~TaskDlgFilletParameters()
 //}
 bool TaskDlgFilletParameters::accept()
 {
+    auto obj = vp->getObject();
+    if (!obj->isError())
+        parameter->showObject();
+
     parameter->apply();
 
     return TaskDlgDressUpParameters::accept();