Fix: gdk-reconfigure fails when symlink for .ruby-version file exists

[ruben@mbp ~/projects/gdk-ce (master *)]$ gdk reconfigure
(in /Users/ruben/projects/gdk-ce)
rm -f \
            gitlab/config/gitlab.yml \
            gitlab/config/database.yml \
            gitlab/config/unicorn.rb \
            gitlab/config/resque.yml \
            gitlab-shell/config.yml \
            redis/redis.conf \
            Procfile
sed -e "s|/home/git|/Users/ruben/projects/gdk-ce|"\
             gitlab/config/gitlab.yml.example > gitlab/config/gitlab.yml
port= support/edit-gitlab.yml gitlab/config/gitlab.yml
  gitlab_shell:
sed "s|/home/git|/Users/ruben/projects/gdk-ce|" database.yml.example > gitlab/config/database.yml
cp gitlab/config/unicorn.rb.example.development gitlab/config/unicorn.rb
echo "listen '/Users/ruben/projects/gdk-ce/gitlab.socket'" >> gitlab/config/unicorn.rb
sed "s|/home/git|/Users/ruben/projects/gdk-ce|" redis/resque.yml.example > gitlab/config/resque.yml
command -v bundler > /dev/null || gem install bundler
sed -e "s|/home/git|/Users/ruben/projects/gdk-ce|"\
              -e "s|^gitlab_url:.*|gitlab_url: http+unix://%2FUsers%2Fruben%2Fprojects%2Fgdk-ce%2Fgitlab.socket|"\
              -e "s|/usr/bin/redis-cli|/usr/local/bin/redis-cli|"\
              -e "s|^  socket: .*|  socket: /Users/ruben/projects/gdk-ce/redis/redis.socket|"\
              gitlab-shell/config.yml.example > gitlab-shell/config.yml
GOPATH=/Users/ruben/projects/gdk-ce/gitlab-workhorse go install gitlab.com/gitlab-org/gitlab-workhorse/...
ln -s /Users/ruben/projects/gdk-ce/gitlab/.ruby-version .ruby-version
ln: .ruby-version: File exists
make: *** [.ruby-version] Error 1

/cc @jacobvosmaer-gitlab