src/meta-openembedded:pure-ftpd: upgrade 1.0.49 -> 1.0.50

License-Update: year updated to 2021.

Changelog
==========
This version fixes some really old issues, the most significant one being
excessive memory use for large memory listings.

When virtual quotas were used, transfers were not aborted after the limit was
reached; files were only removed at the end of a transfer. That should now be fixed.

Support for MD5, SHA1 and the MySQL PASSWORD() function were removed for
password hashing. You should now use scrypt, argon2 or the system crypt(3) function.

The server used to reject class E reserved network ranges. People reported that
Linux containers may use them, so this is now accepted.

Finally, it is now possible to recursively include additional files in a
configuration file, with the new Include directive.

Signed-off-by: Wang Mingyu <[email protected]>
Signed-off-by: Khem Raj <[email protected]>