core: move your_workflow_history to center group

The field needs to be in center group to comply with
https://www.erp5.com/documentation/developer/guideline/module/erp5-Guideline.Module.Creation/#listbox-only-tabs-should-have-a-read-only-title-in-center-group

product/ERP5/bootstrap/erp5_core/SkinTemplateItem/portal_skins/erp5_core/Base_viewZODBHistory.xml

@@ -82,7 +82,9 @@
                 <item>
                     <key> <string>center</string> </key>
                     <value>
-                      <list/>
+                      <list>
+                        <string>your_workflow_history</string>
+                      </list>
                     </value>
                 </item>
                 <item>
@@ -96,9 +98,7 @@
                 <item>
                     <key> <string>left</string> </key>
                     <value>
-                      <list>
-                        <string>your_workflow_history</string>
-                      </list>
+                      <list/>
                     </value>
                 </item>
                 <item>