Passing CSRF token in header not working on NGINX server, as underscores in header are not supported

[JordanRifaey]

@blizzz @akrabat regarding this PR to enable csrf token check in http header: #175

It seems that the CSRF keys have an underscore in them, and NGINX does not support underscores in headers. Is there any way to customize the csrf keys so we can remove the underscore?

[blizzz]

Ok, so that is what @deployHuman referred to in #143 (comment)

Slim-Csrf/src/Guard.php

Line 272 in f66be97

return $this->prefix . '_name';

and

Slim-Csrf/src/Guard.php

Line 280 in f66be97

return $this->prefix . '_value';

would need to be changed.