Add blob: to frame-src Content-Security-Policy

Signed-off-by: Roland Fredenhagen <[email protected]>

lib/Controller/SiteController.php

@@ -100,6 +100,7 @@ protected function createResponse(int $id, array $site, string $path = ''): Temp
 		$policy = new ContentSecurityPolicy();
 		$policy->addAllowedWorkerSrcDomain('*');
 		$policy->addAllowedFrameDomain('*');
+		$policy->addAllowedFrameDomain('blob:');
 		$response->setContentSecurityPolicy($policy);
 
 		return $response;