nio add adds incorrect submodule to etc/blocks.cfg

Using nio-cli 0.7.2, I used nio add and spelled a repository wrong: `nio add webfeed`. I received a fatal error in my terminal. However, in the etc/blocks.cfg file I find it listed as a submodule`{
            "branch":null,
            "path":null,
            "tag":null,
            "url":"git://github.com/nio-blocks/webfeed.git"
        },`