Resolve serialization issue

[bdukes]

Summary

AuthenticationConfigBase is marked as Serializable but has an IServiceProvider property which cannot be serialized (it's a type defined outside of DNN and is not marked as Serializable). This causes an issue when using a caching provider that uses serialization, e.g. https://github.com/davidjrh/dnn.rediscachingprovider

This PR adds the NonSerialized attribute to the property and makes it retrieve the IServiceProvider dynamically (so that it always has a valid value, even after going through serialization).

Fixes #3592

[mitchelsellers]

This looks good to me and should resolve the issue

[ggiordan]

@bdukes thank you so much!!

[ggiordan]

@bdukes I'm confused, I'm looking at the code for the file you changed in the main repo and it looks different that your branch. I see this:

 [Serializable]
    public abstract class AuthenticationConfigBase
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="AuthenticationConfigBase"/> class.
        /// </summary>
        public AuthenticationConfigBase()
        {
            this.DependencyProvider = Globals.DependencyProvider;
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="AuthenticationConfigBase"/> class.
        /// </summary>
        /// <param name="portalID"></param>
        protected AuthenticationConfigBase(int portalID)
            : this()
        {
            this.PortalID = portalID;
        }

        [Browsable(false)]
        public int PortalID { get; set; }

        /// <summary>
        /// Gets the Dependency Provider to resolve registered
        /// services with the container.
        /// </summary>
        /// <value>
        /// The Dependency Service.
        /// </value>
        protected IServiceProvider DependencyProvider { get; }
    }

The code you changed had an [unserializable] decoration. Also, the getter here is different.
Am I looking in the right place?
The reason I ask is that if this is a good fix, I need to patch my running system.

Thanks!!

Jeff

[bdukes]

I had to remove the NotSerialized attribute because it only applies to fields, not properties. The change to the property is all that you should need.

[valadas]

Looks good