Update articles/api-management/self-hosted-gateway-overview.md

Author: tomkerkhove

articles/api-management/self-hosted-gateway-overview.md

@@ -87,7 +87,7 @@ Self-hosted gateways require outbound TCP/IP connectivity to Azure on port 443.
 -   Sending metrics to Azure Monitor, if configured to do so
 -   Sending events to Application Insights, if set to do so
 
-[!INCLUDE [preview](./includes/preview/preview-callout-self-hosted-gateway-deprecation.md.md)]
+[!INCLUDE [preview](./includes/preview/preview-callout-self-hosted-gateway-deprecation.md)]
 
 ### FQDN dependencies