slapos_pdm: update xml format

master/bt5/slapos_pdm/PortalTypeTemplateItem/portal_types/Software%20Product%20Release%20Variation.xml

@@ -68,12 +68,6 @@
               <tuple/>
             </value>
         </item>
-        <item>
-            <key> <string>type_mixin</string> </key>
-            <value>
-              <tuple/>
-            </value>
-        </item>
       </dictionary>
     </pickle>
   </record>

master/bt5/slapos_pdm/PortalTypeTemplateItem/portal_types/Software%20Product%20Type%20Variation.xml

@@ -68,12 +68,6 @@
               <tuple/>
             </value>
         </item>
-        <item>
-            <key> <string>type_mixin</string> </key>
-            <value>
-              <tuple/>
-            </value>
-        </item>
       </dictionary>
     </pickle>
   </record>

master/bt5/slapos_pdm/SkinTemplateItem/portal_skins/slapos_pdm/SoftwareProductTypeVariation_view.xml

@@ -11,9 +11,13 @@
             <value>
               <object>
                 <klass>
-                  <global name="NameAssignments" module="Shared.DC.Scripts.Bindings"/>
+                  <global name="_reconstructor" module="copy_reg"/>
                 </klass>
-                <tuple/>
+                <tuple>
+                  <global name="NameAssignments" module="Shared.DC.Scripts.Bindings"/>
+                  <global name="object" module="__builtin__"/>
+                  <none/>
+                </tuple>
                 <state>
                   <dictionary>
                     <item>