fix: broken tests

[cesarvspr]

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

After:

 FAIL ​ test/global.test.js
 ✖ onRequest hook should be a function, instead got object

          } else if (opts[hook] !== undefined && typeof opts[hook] !== 'function') {
            throw new FST_ERR_HOOK_INVALID_HANDLER(hook, typeof opts[hook])
------------------^
          }
        }

  test: It should add hooks correctly
  stack: |
    Object.addNewRoute (node_modules/fastify/lib/route.js:256:19)
    Object.route (node_modules/fastify/lib/route.js:217:19)
    Object.prepareRoute (node_modules/fastify/lib/route.js:150:18)
    Object._get [as get] (node_modules/fastify/fastify.js:249:34)
    Test.<anonymous> (test/global.test.js:401:11)
  at:
    line: 256
    column: 19
    file: node_modules/fastify/lib/route.js
    function: Object.addNewRoute
  type: FastifyError
  code: FST_ERR_HOOK_INVALID_HANDLER
  statusCode: 500
  tapCaught: returnedPromiseRejection

now: Tests don't break.

[cesarvspr]

fyi: @mcollina @climba03003

[mcollina]

lgtm