Fix missing directory separators when saving podcasts to disk
Summary: SqlPodcastProvider::checkEnclosureLocallyAvailable() and SqlPodcastProvider::downloadResult() strip the trailing slash from the podcast download path, but do not add a directory separator when appending the download filename back to the directory. As a result, downloaded podcast filenames are prefixed with the directory name and stored in the parent directory.
Reviewers: Amarok, heikobecker
Reviewed By: Amarok, heikobecker
Subscribers: heikobecker, Amarok, wbauer, yurchor, amarok-devel
Differential Revision: https://phabricator.kde.org/D24135