Well, that repo they're referring to is apparently not built for Galileo or x86 at all, so it's not going to work. It's like trying to run a program compiled for, say, MIPS on, say, ARM.
Looks like I don't have rsync in my repo at the moment, so you can't just install from there. I'll note to build it, but I won;t be able to do this anytime soon due to other commitments. Maybe in a week or so.
In the meanwhile if you feel up to the task, you can get the devtools image (search for "devtools" in the community), which includes GCC, and try to compile rsync from sources.
Or you can install the dev tools to the official image (see my blog post on that: Installing development tools onto Galileo official Linux image) and try that way. I'd probably recommend the former approach, because you'll get all the tools in a box and won't need topick all teh specific pieces out of the repo.