SSO Config validation causes fatal error before metadata is saved #78
Description
In an environment with the plugin network enabled, entering the network settings page to provide the SSO IdP Metadata provides a broken settings page, as the SSO Config validation field expects the metadata to exist already when viewing the page.
The outcome of this is that it is impossible to save the page, so you are unable to add the metadata to resolve the issue without manually adding the sso_idp_metadata meta key and value to the wp_sitemeta database.