Fixes I/O redirection bug when spawning FreeRadius AP

When spawning a FreeRadius AP an error was occuring during the 

```mv ${pathtoradiusconf}/radiusd.conf ${pathtoradiusconf}/radiusd.conf.back 2&1> /dev/null ``` command

I/O redirection should be ```2>&1 ...``` so I made the fix.

Thanks to [Karthik Rangarajan](https://github.com/karthikrangarajan) for originally pointing out the error