slapos_cloud: Fix Portal Type Definition on Listbox.

master/bt5/slapos_cloud/SkinTemplateItem/portal_skins/slapos_cloud/HostingSubscription_view/my_predecessor_title_list.xml

@@ -91,6 +91,10 @@
                       <list>
                         <tuple>
                           <string>Software Instance</string>
+                          <string>Software Instance</string>
+                        </tuple>
+                        <tuple>
+                          <string>Slave Instance</string>
                           <string>Slave Instance</string>
                         </tuple>
                       </list>