Hi,
I can also see this URL in your log.
It seems like their server is really slow and/or, in your case, this even leads to disconnects.
Even via browser I only get ~5KiB/s which means it would take over 8 days to download this file.
I don't see any JDownloader issue here.
You could try to contact the support of that website and ask them to fix their issues.
Before reporting such issues, please always check against your browser to find out what has caused your issue (see also
this help article).
-psp-
EDIT
Also, when trying to download multiple URLs from that same source at the same time, they might *kill* the connection so you could also try to download only 1 file at the same time from this source.