fix B14020 - unquivering with 'A'

fix B14020 - unquivering with 'A'

     Ahe 'A' command would not let you remove a cursed item from the
quiver or alternate weapon slot.  But other commands such as drop or
quiver would let you get rid of such things since they aren't considered
to be welded in place the way a wielded weapon is.

     This seemingly minor bug is more significant than first appears
because it opens a loophole to allow you determine whether any held item
is cursed:  quiver it, try to remove it with 'A' and possibly be told
that it's cursed, really remove it with 'Q' if so.