Can't install YateBTS with SVN

I can't use the following command to install Yate:

svn checkout -r 5968 http://voip.null.ro/svn/yate/trunk yate

I get the following error when I type the command above in:

svn: E170013: Unable to connect to a repository at URL 'http://voip.null.ro/svn/yate/trunk'svn: E000111: Error running context: Connection refused

I get the same error when typing in

svn checkout -r 5968 http://voip.null.ro/svn/yate/trunk yatebts

On the YateBTS website, this is the correct command to use. What gives? Why is this not working? Is there a fix? It should be noted that I'm currently running Ubuntu 18.04 because I'm using Yate with a USRP N210, so I'm trying to install an older version, which requires an older version of Ubuntu as well.

I've tried opening a port for 5968 but it didn't work. Something tells me that the website is down and I don't know how to fix it.