slapos_subscription_request: set source_project on event

master/bt5/slapos_subscription_request/SkinTemplateItem/portal_skins/slapos_subscription_request/SubscriptionRequestModule_requestSubscriptionProxy.py

@@ -66,7 +66,7 @@ subscription_request = context.subscription_request_module.newContent(
   quantity=user_input_dict["amount"],
   language=target_language,
   specialise_value=subscription_condition,
-  follow_up_value=subscription_condition.getFollowUpValue()
+  source_project_value=subscription_condition.getSourceProjectValue()
 )
 
 subscription_request.setDefaultEmailText(email)