oidc_error.log log level should be kept as "error" by default

[sharma-manish]

The log level for oidc_error.log is defined as "debug" in openid_connect.server_conf. This causes excessive logging, it should be set as error by default and can be changed to debug only in case any debugging is required.

[lcrilly]

There is a new error_log severity configuration since R22.