[Dovecot] (minor) bug in configure

[Sandro Tosi]

Hello,
while reading config options for dovecot v1.2.10 I've noticed a very 
small bug:

# ./configure --help  | egrep -- 'Dovecot|--with-gnu-ld'
`configure' configures Dovecot 1.2.10 to adapt to many kinds of systems.
  --with-gnu-ld           assume the C compiler uses GNU ld [default=no]
  --with-gnu-ld           assume the C compiler uses GNU ld default=no

I think the latter entry should be removed.

Thanks for considering,
Sandro