Backward compatibility for spring-security-oauth2 namespace

[prabhu-radhakrishna]

we need to support both http & https in https://github.com/spring-projects/spring-security-oauth/commits/master/spring-security-oauth2/src/main/resources/META-INF/spring.schemas,, making only https breaks backward compatibility. it should should support like any other spring schemas https://github.com/spring-projects/spring-security/blob/master/config/src/main/resources/META-INF/spring.schemas

even https://github.com/spring-io/nohttp/tree/master/nohttp supports using http for namespace

[jgrandja]

Thanks for the report @prabhu-radhakrishna. Would you be interested in submitting a PR for this fix?