Change: remove the oidc provider in order to upgrad mattn/go-sqlite3 to v1.14.7

in order to upgrade mattn/go-sqlite3 to v1.14.7, the odic provider service is removed, which is possible because it is not used anymore

https://github.com/cs3org/reva/pull/1828
https://github.com/owncloud/ocis/pull/2209
