Multiple usage of `usePdf` doesn't render fonts properly

**Describe the bug**
Registered fonts are applied only for the first document when using `usePdf` multiple times in a single component.

**To Reproduce**
Steps to reproduce the behavior including code snippet (if applies):
1. Create 2 documents
2. Register the same fonts for each of them
```
import robotoMedium from './fonts/Roboto-Medium.ttf'
import robotoRegular from './fonts/Roboto-Regular.ttf'

Font.register({
family: 'Roboto',
fonts: [
{
src: robotoRegular,
fontWeight: 'normal'
},
{
src: robotoMedium,
fontWeight: 'medium'
}
]
})
```
3. Apply fonts in styles for both documents
4. Create a component
5. Import both documents
6. use `usePdf` twice in the created component:
```
const [instanceOne] = usePdf({ document: })
const [instanceTwo] = usePdf({ document: })
```
7. Add anchor tag and download both PDFs

**Actual behavior**

Downloading both `instanceOne` and `instanceTwo` results in displaying proper fonts only for `instanceOne`.

If I'd change the order and it will be:
```
const [instanceTwo] = usePdf({ document: })
const [instanceOne] = usePdf({ document: })

```

Then the `instanceTwo` is rendered properly and `instanceOne` is not.

**Expected behavior**
Fonts should be rendered properly for both documents

**Desktop (please complete the following information):**
- OS: Ubuntu
- Browser: Chrome
- React-pdf version v2.1.1