Fix URL in squeal.spec
    
    I moved https://fedorahosted.org/squeal/ to https://github.com/davidmalcolm/squeal on 2017-02-06 due to the fedorahosted.org sunset (on 2017-02-28).

    

    I'm not yet sure where tarballs should live (so Source0 isn't right yet).

    

    This also doesn't update the Release