MDL-28221 Legacy resource URL pointing to the course itself are migrated as File module
MDL-28221 Legacy resource URL pointing to the course itself are migrated as File module

This patch replays the logic of resource_20_migrate() function. If a
file is referred via URL to the course files of the course being
backed up, then such a resource is converted to the File module
(mod/resource) rather than URL module.

dilawar/moodle