profile-service is returning text/html as the content type for JSONP responses

[ansell]

Yesterday we debugged an issue where the cause was profile-service returning text/html instead of text/javascript for JSONP responses. This caused the browser to fail the request when the security header X-Content-Type-Options: nosniff was enabled. Temporarily patched nginx to not include the nosniff header, but the bug of returning text/html as the content type for these JSONP responses should be fixed so that the security header can be switched on again.