Preventing the internal spell checker from finding the first occurrence of

Preventing the internal spell checker from finding the first occurrence of
a misspelled word twice.  And deleting the piece of dead code that was meant
to do this.  This fixes Savannah bug #47188.

When we've reached again the same line where we started and we find an
instance there, then this can only be /before or at/ the position from
where we started, otherwise we would have found it when we commenced
searching.  And so... that little piece of dead code does absolutely
nothing -- it will never fire.

It's so nice... nano is full of Easter Eggs!  :)

git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@5760 35c25a1d-7b9e-4130-9fde-d3aeb78583b8