test: http2 connectionListener reject client

This code change modifies connectionListener tests to cover a test case where this.emit('unknownProtocol', socket) returns false

https://github.com/nodejs/node/blob/e0122299cf4ee7d97ca826a8f68eb799a5a56fe7/lib/internal/http2/core.js#L2284-L2287

Refs: https://github.com/nodejs/node/issues/14985

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• commit message follows commit guidelines

Affected core subsystem(s)

test, http2