Bug: if not CSPEnaled but i have some 

**Describe the bug**
if for test change app.CSPEnabled from true to false
BUT if 
into initController i used $response->CSP->addStyleSrc('https://fonts.googleapis.com');

Return an error "Call to a member function addStyleSrc() on null "

**CodeIgniter 4 version**
RC-3

**Context**
 - OS: Win
 - Web server Apache
 - PHP version 7.3
