Update description when tree item is in editor.

Fixes: lp:1820298
* https://bugs.launchpad.net/kicad/+bug/1820298

pcbnew/fp_tree_synchronizing_adapter.cpp

@@ -175,6 +175,9 @@ void FP_TREE_SYNCHRONIZING_ADAPTER::GetValue( wxVariant& aVariant, wxDataViewIte
         break;
 
     case 1:
+        if( node->LibId == m_frame->GetLoadedFPID() && !m_frame->IsCurrentFPFromBoard() )
+            aVariant = m_frame->GetBoard()->m_Modules->GetDescription();
+        else
             aVariant = node->Desc;
         break;