Add `<meta name="twitter:widgets:csp" content="on">`.
Add `<meta name="twitter:widgets:csp" content="on">`.

https://dev.twitter.com/web/overview/widgets-webpage-properties#disable-functionality-which-may-trigger-content-security-policy-warnings

MaxCDN/bootstrap-cdn,MaxCDN/bootstrap-cdn,MaxCDN/bootstrap-cdn