http2: set default maxConcurrentStreams

Set the default maxConcurrentStreams to
NGHTTP2_DEFAULT_MAX_CONCURRENT_STREAMS.

PR-URL: https://github.com/nodejs/node/pull/29833
Fixes: https://github.com/nodejs/node/issues/29763
Refs: https://github.com/nghttp2/nghttp2/commit/16c46114dc724278beaa6d59462f8396f35fa4a9


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>