Try to restart a mirrorlist-server process if not running
    
    Sometimes we see that mirrorlist-server processes are not running and it
    just needs to be restarted. Let the script try it twice before erroring
    out.
    
    The most common reason for non running mirrorlist-server processes seems
    to be incomplete or truncated input files which is usually fixed the
    next time the data is synced.
    
    Signed-off-by: Adrian Reber <adrian@lisas.de>