uftp: 4.9.5 -> 4.9.6

Semi-automatic update generated by https://github.com/ryantm/nixpkgs-update tools.

This update was made based on information from https://repology.org/metapackage/uftp/versions.

These checks were done:

- built on NixOS
- ran ‘/nix/store/97wm1cjgqd5ih45689h2xmqfv7ywv8bi-uftp-4.9.6/bin/uftpd help’ got 0 exit code
- ran ‘/nix/store/97wm1cjgqd5ih45689h2xmqfv7ywv8bi-uftp-4.9.6/bin/uftp_keymgt -h’ got 0 exit code
- ran ‘/nix/store/97wm1cjgqd5ih45689h2xmqfv7ywv8bi-uftp-4.9.6/bin/uftp_keymgt --help’ got 0 exit code
- ran ‘/nix/store/97wm1cjgqd5ih45689h2xmqfv7ywv8bi-uftp-4.9.6/bin/uftp_keymgt help’ got 0 exit code
- found 4.9.6 with grep in /nix/store/97wm1cjgqd5ih45689h2xmqfv7ywv8bi-uftp-4.9.6
- directory tree listing: https://gist.github.com/c08d432d7a238559a904561aa46161bd