InputNumber throws error if emptied

[Rakasch]

steps to reproduce:

1. focus the InputNumber field (it should have some value in it)
2. hit the "end" key
3. press "shift+pos1" to mark the value
4. press "Del"

it will throw an error in console window.

Chrome-Error

chunk-vendors.8ef82b9e.js:7 
TypeError: Cannot set property 'value' of undefined
    at a.onInput (app.5c814089.js:1)
    at input (app.5c814089.js:1)
    at ne (chunk-vendors.8ef82b9e.js:7)
    at a.n (chunk-vendors.8ef82b9e.js:7)
    at ne (chunk-vendors.8ef82b9e.js:7)
    at a.An.t.$emit (chunk-vendors.8ef82b9e.js:7)
    at input (app.5c814089.js:1)
    at ne (chunk-vendors.8ef82b9e.js:7)
    at HTMLInputElement.n (chunk-vendors.8ef82b9e.js:7)
    at HTMLInputElement.Ki.o._wrapper (chunk-vendors.8ef82b9e.js:7)

FireFox-Error

TypeError: e.target is undefined
    onInput https://www.primefaces.org/primevue/showcase/js/app.5c814089.js:1
    input https://www.primefaces.org/primevue/showcase/js/app.5c814089.js:1
    ne https://www.primefaces.org/primevue/showcase/js/chunk-vendors.8ef82b9e.js:7
    n https://www.primefaces.org/primevue/showcase/js/chunk-vendors.8ef82b9e.js:7
    ne https://www.primefaces.org/primevue/showcase/js/chunk-vendors.8ef82b9e.js:7
    $emit https://www.primefaces.org/primevue/showcase/js/chunk-vendors.8ef82b9e.js:7
    input https://www.primefaces.org/primevue/showcase/js/app.5c814089.js:1
    ne https://www.primefaces.org/primevue/showcase/js/chunk-vendors.8ef82b9e.js:7
    n https://www.primefaces.org/primevue/showcase/js/chunk-vendors.8ef82b9e.js:7
    _wrapper https://www.primefaces.org/primevue/showcase/js/chunk-vendors.8ef82b9e.js:7