www: fix alignments in channelinfo hosts table
    
    Use the "data-list" classes to style the Hosts table in the channelinfo
    page. This makes the header row stand out and easier to read, matching
    the rest of the data tables in kojiweb.
    
    This change also fixes a problem in some downstream themes. For example,
    Fedora's theme and Brew's theme set "text-align: right" for all tbody.th
    elements. These themes do this in order to control the larger parent
    "info" table header cells, but it ends up mis-aligning un-classed
    sub-tables like this one. With this change, the "list-header" class
    left-aligns the header row text, and the "data-list" class left-aligns
    the final text.