Updated clientState

`clientState` should be `clientState` and not `client-clientState`

Author: wictorwilen

docs/apis/webhooks/lists/create-subscription.md

@@ -45,7 +45,7 @@ Name | Type | Description
 resource|string|The URL of the list to receive notifications from.
 notificationUrl|string|The service URL to send notifications to.
 expirationDateTime|date|The date the notification will expire and be deleted.
-client-clientState|string|Optional. Opaque string passed back to the client on all notifications.<br/>You can use this for validating notifications or tagging different subscriptions.
+clientState|string|Optional. Opaque string passed back to the client on all notifications.<br/>You can use this for validating notifications or tagging different subscriptions.
 
 
 ### Example
@@ -89,4 +89,4 @@ If your service fails to validate the request in this way, the subscription is n
 ## See also
 
 - [SharePoint list webhooks](overview-sharepoint-list-webhooks.md)
-- [Overview of SharePoint webhooks](../overview-sharepoint-webhooks.md)
+- [Overview of SharePoint webhooks](../overview-sharepoint-webhooks.md)