aria2 1.18.3 released

aria2 is a lightweight multi-protocol & multi-source, cross platform download utility operated in command-line. It supports HTTP/HTTPS, FTP, BitTorrent and Metalink.

This release fixes the bug which may cause assertion failure after
multi-file downloads (e.g., multi-file metalink or torrent) are
performed several times due to the bad handling of --bt-max-open-files
option.