systemvm-template URL fix for 4.13 (apache#123)

Author: andrijapanicsb

source/quickinstallationguide/qig.rst

@@ -494,7 +494,7 @@ the system VMs images.
   
    /usr/share/cloudstack-common/scripts/storage/secondary/cloud-install-sys-tmplt \
    -m /export/secondary \
-   -u http://download.cloudstack.org/systemvm/4.11/systemvmtemplate-4.11.2-kvm.qcow2.bz2 \
+   -u |sysvm64-url-kvm| \
    -h kvm -F