BZ#2118733: CNV: Add note about LM encryption

Author: Bob Gaydos

modules/virt-about-live-migration.adoc

@@ -13,4 +13,6 @@ You can use live migration if the following conditions are met:
 
 * Shared storage with `ReadWriteMany` (RWX) access mode.
 * Sufficient RAM and network bandwidth.
-* If the virtual machine uses a host model CPU, the nodes must support the virtual machine's host model CPU.
+* If the virtual machine uses a host model CPU, the nodes must support the virtual machine's host model CPU.
+
+By default, live migration traffic is encrypted using Transport Layer Security (TLS).