text: Title: xml extraction leads to <graphic> tags in the wrong place.
  Body: ```
  import trafilatura
  downloaded = trafilatura.fetch_url('https://en.wikipedia.org/wiki/Laplace_distribution')
  ex=trafilatura.extract(downloaded,output_format='xml',include_images=True)
  print(ex)
  ```
  In several places, I see a `<graphic>...</graphic>` region in the wrong place.
  For example, trafilatura produces
  ```
      <p>where <graphic> is the generalized exponential integral function </graphic></p>
  ```
  from
  ![image](https://user-images.githubusercontent.com/144178/148621885-f690dd3f-8ba9-4760-bbd3-03a5815d4c89.png)
  