Update overview.md

removing preview reference from AGC on what is WAF page

Author: Miskatonic-Electronic

articles/web-application-firewall/overview.md

@@ -34,7 +34,7 @@ Azure Web Application Firewall can be deployed with these Microsoft services:
 - Azure Front Door
 - Azure Content Delivery Network
 
-Azure Web Application Firewall on Azure Content Delivery Network and Azure Web Application Firewall on Application Gateway for Containers are currently in preview. Azure Web Application Firewall has features that are customized for each specific service.
+Azure Web Application Firewall on Azure Content Delivery Network is currently in preview. Azure Web Application Firewall has features that are customized for each specific service.
 
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