Update disk-encryption.md

Author: jofrance

articles/virtual-machines/linux/disk-encryption.md

@@ -68,7 +68,7 @@ For now, customer-managed keys have the following restrictions:
 - All resources related to your customer-managed keys (Azure Key Vaults, disk encryption sets, VMs, disks, and snapshots) must be in the same subscription and region.
 - Disks, snapshots, and images encrypted with customer-managed keys cannot move to another subscription.
 - If you use the Azure portal to create your disk encryption set, you cannot use snapshots for now.
-- Virtual machines encrypted using encryption at rest with customer managed keys cannot be encrypted using Azure Disk Encryption.
+- Managed disks encrypted using customer-managed keys cannot also be encrypted with Azure Disk Encryption.
 
 ### CLI
 #### Setting up your Azure Key Vault and DiskEncryptionSet