Add blob to csp (#399)

Author: YHhaoareyou

root/src/index.ejs

@@ -16,7 +16,7 @@
     This CSP allows any SSL-enabled host and for arbitrary eval(), but you should limit these directives further to increase your app's security.
     Learn more about CSP policies at https://content-security-policy.com/#directive
   -->
-  <meta http-equiv="Content-Security-Policy" content="default-src 'self' https: blob:* localhost:*; script-src 'unsafe-inline' 'unsafe-eval' https: localhost:*; connect-src https: localhost:* ws://localhost:*; style-src 'unsafe-inline' https: localhost:*; object-src 'none'; img-src 'self' https: localhost:* data: http://books.google.com http://cdn.viglink.com; font-src 'self' https: localhost:* data:;">
+  <meta http-equiv="Content-Security-Policy" content="default-src 'self' blob: https: localhost:*; script-src 'unsafe-inline' 'unsafe-eval' blob: https: localhost:*; connect-src https: localhost:* ws://localhost:*; style-src 'unsafe-inline' https: localhost:*; object-src 'none'; img-src 'self' https: localhost:* data: http://books.google.com http://cdn.viglink.com; font-src 'self' https: localhost:* data:;">
   <meta name="importmap-type" content="systemjs-importmap" />
   <!-- If you wish to turn off import-map-overrides for specific environments (prod), uncomment the line below -->
   <!-- More info at https://github.com/joeldenning/import-map-overrides/blob/master/docs/configuration.md#domain-list -->