Bought a 'd' - fixed an old typo

Bought a 'd' - fixed an old typo

'bandwith...' should be 'bandwidth...'.

Despite being my favourite typo for the past few years(?),
today I decided to try to say 'Goodbye' to an old friend.

Similar to 'MB writen' its hard but I think it just about time.

'qos' and 'guardian' will never be the same for me... ;-)

Signed-off-by: Matthias Fischer <matthias.fischer@ipfire.org>
Reviewed-by: Adolf Belka <adolf.belka@ipfire.org>
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>