rsync: override to disable ACL

Same as the BSDs.

overlay/default.nix

@@ -89,6 +89,8 @@ in {
       "rm $out/bin/c_rehash"; # eliminate the perl runtime dependency
   });
 
+  rsync = overrideHost rsync { enableACLs = false; };
+
   solo5-tools = callPackage ./solo5-tools { };
 
   tup = prev.tup.overrideAttrs (attrs: { setupHook = ./tup/setup-hook.sh; });