Fix OIDC unit tests
Fix OIDC unit tests

- Fixed username assertion check. SGW now returns the username with <issuer>-<userid>_<subject>. But if the issuer contains any invalid characters (underscore, forward slash), the issuer name will be hashed (https://github.com/couchbase/sync_gateway/commit/5077268a4a5414d74fa947063171ef8f7f985f51).

- Used non-SSL db URL for testing OIDC with the test provider. Opened issue for using HTTPS (https://github.com/couchbase/couchbase-lite-ios/issues/1308).

couchbase/couchbase-lite-ios,amco/couchbase-lite-ios,couchbase/couchbase-lite-ios,amco/couchbase-lite-ios,amco/couchbase-lite-ios,couchbase/couchbase-lite-ios,amco/couchbase-lite-ios,couchbase/couchbase-lite-ios,amco/couchbase-lite-ios,amco/couchbase-lite-ios,couchbase/couchbase-lite-ios,couchbase/couchbase-lite-ios,amco/couchbase-lite-ios