http2: remove unsupported %.* specifier

The debug sprintf doesn't support %.* specifiers

Fixes: https://github.com/nodejs/node/issues/35688

PR-URL: https://github.com/nodejs/node/pull/35694


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Ricky Zhou <0x19951125@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>