Removed miss-placed space in discovery-url command

When running make discovery-url I got this error message:
sed -i .orig -e "s,# discovery: https://discovery.etcd.io/12345693838asdfasfadf13939923,discovery: $(curl -s -w '\n' https://discovery.etcd.io/new)," contrib/coreos/user-data
sed: can't read .orig: No such file or directory
make: *** [discovery-url] Error 2

By removing the space it worked as expected and I could run vagrant up to start up the cluster.