New Content-Security-Policy prevents External Links from being opened

[TheWitness]

Describe the bug

The extremely restrictive new CSP causes External Links to break. Need to allow more permissive policy to allow them to work.

To Reproduce

1. Install Cacti 1.2.11
2. Create and External Link to cacti.net
3. Attempt to Access that link
4. See in the browsers debugger, that the CSP prevented that

Expected behavior

By default, Cacti should allow External links.