slapos_crm: Fixup! Ticket use a script to get its causality

See merge request nexedi/slapos.core!414

master/bt5/slapos_crm/SkinTemplateItem/portal_skins/slapos_crm_monitoring/SupportRequest_checkCausalitySourceDestinationConsistency.py

-portal = context.getPortalObject()
-event = context.getCausalityValue(portal_type=portal.getPortalEventTypeList())
+event = context.Ticket_getCausalityValue()
 error_list = []
 
 if event: