at0m

This is a bit of a necro, but if all you want is the warning to go away, at the top level under the service put memlimit_swap: -1 and  it'll stop throwing the warning.
 
Posting here since this is the top hit on Google when I searched for the warning text and unraid.

My point being the SEO on the documentation search function is garbage if the top hit is useless info. I understand this is essentially a volunteer effort (which is a little odd for paid software, but that's a different story), but my first instinct when looking at documentation is not to read the whole first page which is generally useless, I _search_. And search in this case is pointing to the wrong thing, as both OP and I found.