I'm pretty sure an error like that is due to your own proxy server's defined security policies. Plone does not OOTB, define any security policies for loading scripts.
The current policy you seem to have in place is safe but sounds like it's too restrictive for your use-case.
You can try placing that file in your theme/site and loading from there or checking your configuration. If you share your domain, someone here can tell you what header is causing it.