🐛 Bug Report

If an async hook returns a Promise.reject() the flow continue.
This usage of promise should be avoided at all, let me know if you think this is an invalid bug.

Here we should check the err param

To Reproduce

Steps to reproduce the behavior:

const fastify = require('./fastify')({ logger: true })
fastify.addHook('onRequest', function (request, reply) {
  return Promise.reject()
})
fastify.get('/', async (request, reply) => { return 'hi' })
fastify.listen(3001)

Expected behavior

The rejection should be managed.

Originally posted by @Eomm in fastify/help#135 (comment)