slapos_cloud: Protect supply against multiple calls on the same request

  This prevents +2 supplies on the request creates more them one software installation with same url on a compute  node.

master/bt5/slapos_cloud/WorkflowTemplateItem/portal_workflow/compute_node_slap_interface_workflow/script_ComputeNode_requestSoftwareReleaseChange.py

@@ -14,7 +14,7 @@ except KeyError:
 tag = "%s_%s_inProgress" % (compute_node.getUid(), 
                                software_release_url)
 
-if (portal.portal_activities.countMessageWithTag(tag) > 0):
+if (portal.portal_activities.countMessageWithTag(tag) > 0 or compute_node.REQUEST.get(tag) == tag):
   # The software instance is already under creation but can not be fetched from catalog
   # As it is not possible to fetch informations, it is better to raise an error
   raise NotImplementedError(tag)
@@ -41,7 +41,7 @@ else:
   if (state == "destroyed"):
     # No need to create destroyed subscription.
     return
-  software_installation_reference = "SOFTINSTALL-%s" % context.getPortalObject().portal_ids\
+  software_installation_reference = "SOFTINSTALL-%s" % portal.portal_ids\
       .generateNewId(id_group='slap_software_installation_reference', id_generator='uid')
   software_installation = portal.getDefaultModule(portal_type=software_installation_portal_type).newContent(
     portal_type=software_installation_portal_type,
@@ -51,6 +51,7 @@ else:
     follow_up_value=compute_node.getFollowUpValue(),
     activate_kw={'tag': tag}
   )
+  compute_node.REQUEST.set(tag, tag)
 
 # Change desired state
 if (state == "available"):
@@ -67,4 +68,4 @@ if validation_state == 'draft':
   portal.portal_workflow.doActionFor(software_installation,
                                            'validate_action')
 
-context.REQUEST.set('software_installation_url', software_installation.getRelativeUrl())
+compute_node.REQUEST.set('software_installation_url', software_installation.getRelativeUrl())