Description for third party delivery networks does not consider intranet usage

In Load settings, the description for "Allow usage of third party content delivery networks" is (ALLOW_CDN_EXPLAIN):

If this setting is enabled, some files will be served from external third party servers instead of your server. This reduces the network bandwidth required by your server, but may present a privacy issue for some board administrators. In a default phpBB installation, this includes loading “jQuery” and the font “Open Sans” from Google’s content delivery network.

This description does not consider intranet usage of phpBB. In this situation

• usage of CDNs may not be possible (no internet access)
• usage of CDNs may be an unwanted situation due to network costs

A short note about this should be added to the description.