RequestHeaders option not binding correctly from config

[skwasjer]

When binding CorrelateOptions via env var or JSON, it is not correctly 'overwriting' the default value.

Actual

IConfigurationRoot config = new ConfigurationBuilder()
    .AddInMemoryCollection(
        new Dictionary<string, string?>
        {
            { "RequestHeaders:0", "Header1" },
            { "RequestHeaders:1", "Header2" }
        }
    )
    .Build();

using ServiceProvider services = new ServiceCollection()
    .Configure<CorrelateOptions>(config.Bind)
    .BuildServiceProvider();

CorrelateOptions opts = services.GetRequiredService<IOptions<CorrelateOptions>>().Value;

opts.RequestHeaders here contains ["X-Correlation-Id", "Header1", "Header2]". Effectively, the configured values are appended instead of overwriting the default value.

Expected

The RequestHeaders to only contain the configured values ["Header1", "Header2"]