MyBS: Fix upload to OBS.
    
    When a cookie is received and SSH authentication is not used osc_wrapper
    crashes with message:
    
    Can't use an undefined value as a symbol reference at MyBS.pm line 290.
    
    Fix this by not trying to save cookies for plain authentication.
    
    Signed-off-by: Michal Suchanek <msuchanek@suse.de>