Added supported OS list

Author: memildin

articles/security-center/built-in-vulnerability-assessment.md

@@ -41,7 +41,7 @@ To deploy the vulnerability scanner extension:
     Your VMs will appear in one or more of the following groups:
     * **Healthy resources** – the vulnerability scanner extension has been deployed to these VMs.
     * **Unhealthy resources** – the vulnerability scanner extension can be deployed to these VMs. 
-    * **Not applicable resources** – These VMs can’t have the vulnerability scanner extension deployed. Your VM might be in this tab because it's on the free pricing tier, or running an unsupported OS.
+    * **Not applicable resources** – These VMs can’t have the vulnerability scanner extension deployed. Your VM might be in this tab because it's on the free pricing tier, or it's not running one of the supported OSes (RHEL 6.7/7.6, Ubuntu 14.04/18.04, Centos 6.10/7/7.6, Oracle Linux 6.8/7.6, SUSE 12/15, and Debian 7/8). 
 
 1. From the Unhealthy resources tab, select the VMs on which you want to deploy the Qualys scanner and click **Remediate**.