FIX: parameters modify of printer preset

Ensure correct behavior when modifying parameters of printer preset

Change-Id: Ic627a8e202bf4224b742336cc43ac611ddc5c997
(cherry picked from commit 366a14d8f715cbeca3d0f70a4727d91b6f0ca82e)

src/slic3r/GUI/Widgets/ComboBox.cpp

@@ -160,6 +160,7 @@ int ComboBox::Append(const wxString &item,
     icons.push_back(bitmap);
     datas.push_back(clientData);
     types.push_back(wxClientData_None);
+    SetClientDataType(wxClientData_Void);
     drop.Invalidate();
     return texts.size() - 1;
 }