#987 Usage login prevents from user deletion

git-svn-id: http://svn.code.sf.net/p/itop/code/trunk@3320 a333f486-631f-4898-b8df-5754b55c2be0

core/event.class.inc.php

@@ -351,7 +351,7 @@ class EventLoginUsage extends Event
 		MetaModel::Init_Params($aParams);
 		MetaModel::Init_InheritAttributes();
 
-		MetaModel::Init_AddAttribute(new AttributeExternalKey("user_id", array("targetclass"=>"User", "jointype"=> "", "allowed_values"=>null, "sql"=>"user_id", "is_null_allowed"=>false, "on_target_delete"=>DEL_MANUAL, "depends_on"=>array())));
+		MetaModel::Init_AddAttribute(new AttributeExternalKey("user_id", array("targetclass"=>"User", "jointype"=> "", "allowed_values"=>null, "sql"=>"user_id", "is_null_allowed"=>false, "on_target_delete"=>DEL_SILENT, "depends_on"=>array())));
 		$aZList = array('date', 'user_id');
 		if (MetaModel::IsValidAttCode('Contact', 'name'))
 		{