Attribute filter warnings in the IdP log since installing the OIDC extension

[Rod Widdowson]

> For nearly every authentication since adding the OIDC extension to our IdP, we see the following warnings in our IdP log. 

To confirm what Scott said, these warnings *do* matter.  

The situation is very distinct from a filter returning no values:  they indicate that a failure occurred during attribute filtering
and as a result the entire filter failed safe to "no release" (if it was a deny filter is would fail safe to "deny all").

You/we need to find out why the failure occurred, not least because the source of the failure should also be logging,  This lack of
previous warning at least requires a bug fix.

It would be useful to see what a log at debug of "net.shibboleth.idp.filter" says.

Thanks

	Rod