in do_replace_loop(), treat real_current as current and real_current_x

in do_replace_loop(), treat real_current as current and real_current_x
as current_x instead of using copies of them (which aren't kept up to
date) when calling findnextstr(); this fixes a problem where the search
can wrap when it shouldn't and skip over all matches after the wrap
point

git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@2119 35c25a1d-7b9e-4130-9fde-d3aeb78583b8