I am trying to install this plugin on DM520 with Open Pli but getting this error -

Connecting to tunisia-dreambox.info (198.54.116.160:80)
/bin/sh: is: not found
- 100% |*****************************************************************************************************| 2796 0:00:00 ETA
[Your device is MIPS - DM520/525]

Downloading http://downloads.openpli.org/feeds/openpli-6-release/3rd-party-dm520/Packages.gz.
wget: server returned error: HTTP/1.1 404 Not Found
Downloading http://downloads.openpli.org/feeds/openpli-6-release/3rd-party/Packages.gz.
Updated source 'openpli-3rd-party'.
Downloading http://openpli.japhar.net/feeds/openpli-7.3star/all/Packages.gz.
Updated source 'openpli-all'.
Downloading http://openpli.japhar.net/feeds/openpli-7.3star/dm520/Packages.gz.
Updated source 'openpli-dm520'.
Downloading http://openpli.japhar.net/feeds/openpli-7.3star/mips32el/Packages.gz.
Updated source 'openpli-mips32el'.
Downloading http://downloads.openpli.org/feeds/openpli-6-release/picons/Packages.gz.
Updated source 'openpli-picons'.
Collected errors:
* opkg_download_backend: Failed to download http://downloads.openpli.org/feeds/openpli-6-release/3rd-party-dm520/Packages.gz, wget returned 1.
Missing (pigz) package
root@dm520:~#