extra-files: use -p, -FF

After removing -a in nix-community#15, remote extra files are implictly chowned
according to the remote umask. So we (re-)add --perms to apply local
file permissions remotely as this should mostly be expected behavior.

The second -F disables uploading the .rsync-filter file itself if it exists.

src/nixos-remote.sh

@@ -244,7 +244,7 @@ if [[ -n ${extra_files:-} ]]; then
   if [[ -d $extra_files ]]; then
     extra_files="$extra_files/"
   fi
-  rsync -vrlF -e "ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no" "$extra_files" "${ssh_connection}:/mnt/"
+  rsync -rlpv -FF -e "ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no" "$extra_files" "${ssh_connection}:/mnt/"
 fi
 
 ssh_ <<SSH