Add linebreak in one-time backup settings

When running a manual, one-time backup, if you check the elipses after “Include any files in the backup” it expands a few options for plugins, themes, etc.

However, it also lists “Send this backup to remote storage” without any additional linebreak or vertical space, so it looks like it’s in the same list. If, say, you want to backup just uploads, it’s very easy to accidentally un-check the remote storage option, because it looks like it’s in the same list.

Just an extra linebreak there would save some goofs for people like me who work quickly. :)