Documentation: fix example qemu URL
Documentation: fix example qemu URL

Two slashes instead of three lead to an obscure CA related error message:

http://wiki.libvirt.org/page/Failed_to_connect_to_the_hypervisor#Cannot_read_CA_certificate
dmacvicar/terraform-provider-libvirt,deasmi/terraform-provider-libvirt,flavio/terraform-provider-libvirt,dmacvicar/terraform-provider-libvirt,deasmi/terraform-provider-libvirt,deasmi/terraform-provider-libvirt,dmacvicar/terraform-provider-libvirt