Deletes a System.Net.NetworkCredential instance from the cache if it is associated with the specified host, port, and authentication protocol.
This method removes a System.Net.NetworkCredential instance from the System.Net.CredentialCache if the specified host, port, and authentication protocol match those associated with the credential. Multiple calls to the CredentialCache.Remove(string, int, string) method for the same System.Net.NetworkCredential have no effect.
If authType is null or uriPrefix is null, or no matching credential is found in the cache, this method does nothing.