Nextcloud: Update php-saml library to 2.10.5

The php-saml library as used by our SSO implementation had a minor security patch in 2.10.4 as per https://github.com/onelogin/php-saml/commit/949359f5cad5e1d085c4e5447d9aa8f49a6e82a1. So we should update this in our next minor releases. Security update for signature validation on...

An error during signature verification can be treated as a successful verification.

Security update for signature validation on LogoutRequest/LogoutResponse. In order to verify Signatures on Logoutrequests and LogoutResponses we use the verifySignature of the class XMLSecurityKey from the xmlseclibs library. That method end up calling opensslverify depending on the signature...