Update default HTTP/2 settings

[aryan-25]

Motivation:

As part of passing the HTTP/2 configuration values to NIOHTTP2Handler, we override NIOHTTP2Handler's ConnectionConfiguration's initialSettings.

This means we do not use the sensible defaults provided for ConnectionConfiguration's initialSettings by the nioDefaultSettings property, which sets maxConcurrentStreams to 100, and maxHeaderListSize to 1 << 14.

Modifications:

• Updated the value of the internal defaultMaxConcurrentStreams property and the public maxConcurrentStreams property in NIOHTTPServerConfiguration.HTTP2 from nil (translates to no limit on the max concurrent streams) to 100.

  • The types of these properties were also updated from Int? to Int, which also required the initializer to be updated. Users can no longer express unlimited maxConcurrentStreams and must either provide a concrete limit or implicitly use the default value of 100.
  • Updated the swift-configuration integration to reflect this change.

• Added the values contained in nioDefaultSettings to the initial settings array that we override.

• Raised the swift-nio-http2 dependency version to 1.44.0 in order to use the NIOHPACK product, which provides the default value for maxHeaderListSize.

Result:

We now set sensible default HTTP/2 settings.