Fix the ordering of the issues by priority using JS and its documentation
    
    Basically the documentation was saying the opposite of what the JS is
    doing but then the JS was somehow not getting properly initialized.
    This commit fixes both issues.
    
    Fixes https://pagure.io/pagure/issue/2478
    
    Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>