slapos_erp5: Include missing selection name on listbox

master/bt5/slapos_erp5/SkinTemplateItem/portal_skins/slapos_base/ContractInvitationToken_view/listbox.xml

@@ -555,7 +555,7 @@
                 </item>
                 <item>
                     <key> <string>selection_name</string> </key>
-                    <value> <string></string> </value>
+                    <value> <string>cloud_invitation_cloud_contract_line_selection</string> </value>
                 </item>
                 <item>
                     <key> <string>sort</string> </key>