don't try to inject nonce attributes into RedirectResponse content

[marcogrueter]

Great plugin, thank you very much for that!

When trying it out, I noticed that the redirect from Rainlabs translate plugin, in connection with the forceURLScheme setting, was visible on the page for a short time. I guess this is because the redirect is built during runtime and comes as a response to a page render.

Since RedirectResponses don't have anything to decorate anyway, it should be safe to just skip the nonce injection for this kind of content/response.

I am not 100% sure if it is a perfect solution, but it solves this problem.
There might be other kinds of content in the "dataHolder", but since the "normal" content is a string , I'm not sure if a reversed check (whitelisting content that should have nonce injected instead of blacklisting content like the RedirectResponse) is possible.

[tobias-kuendig]

Very good point and great addition, thank you!