Deletion of IdP metadata does not remove it from list of avaialable IdP

[kabalin]

What happened?

When I change IdP Metadata on the site that was configured and set idpmetadata to empty value and save, I expect this to remove it from the list of available IdPs, this does not happen, the entity is still listed when I click on "Select available IdPs" and login page outputs warning:

Missing IdP metadata configuration for 'http://samlidp.local:8080/simplesaml/saml2/idp/metadata.php'
line 248 of /auth/saml2/classes/auth.php: call to debugging()
line 736 of /lib/authlib.php: call to auth_saml2\auth->loginpage_idp_list()
line 124 of /auth/classes/output/login.php: call to auth_plugin_base::get_identity_providers()
line 377 of /login/index.php: call to core_auth\output\login->__construct()

What you expected:

Setting idpmetadata to empty value should remove entitiy from the list of available IdPs.