fix file type

Author: tamram

articles/storage/common/network-routing-preferences.md

@@ -27,7 +27,7 @@ You can change the routing configuration for your storage account so that both i
 
 The following diagram shows how traffic flows between the client and the storage account for each routing preference:
 
-![Overview of routing options for Azure Storage](media/network-routing-preferences/routing-options-diagram.jpg)
+![Overview of routing options for Azure Storage](media/network-routing-preferences/routing-options-diagram.png)
 
 ## Routing configuration