Minor fix in Transformers Notebook
Minor fix for the German example sentence in notebook :)
# [Codecov](https://codecov.io/gh/huggingface/transformers/pull/4025?src=pr&el=h1) Report
> Merging [#4025](https://codecov.io/gh/huggingface/transformers/pull/4025?src=pr&el=desc) into [master](https://codecov.io/gh/huggingface/transformers/commit/2fade302ac55a289f00c61b0947a8e00dadf41fe&el=desc) will **increase** coverage by `0.00%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/huggingface/transformers/pull/4025/graphs/tree.svg?width=650&height=150&src=pr&token=9qOlN6Hb1c)](https://codecov.io/gh/huggingface/transformers/pull/4025?src=pr&el=tree)

```diff
@@           Coverage Diff           @@
##           master    #4025   +/-   ##
=======================================
  Coverage   78.51%   78.51%           
=======================================
  Files         111      111           
  Lines       18486    18486           
=======================================
+ Hits        14514    14515    +1     
+ Misses       3972     3971    -1     
```


| [Impacted Files](https://codecov.io/gh/huggingface/transformers/pull/4025?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [src/transformers/modeling\_tf\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/4025/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl91dGlscy5weQ==) | `92.59% <0.00%> (-0.17%)` | :arrow_down: |
| [src/transformers/modeling\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/4025/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ191dGlscy5weQ==) | `91.06% <0.00%> (+0.12%)` | :arrow_up: |
| [src/transformers/file\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/4025/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9maWxlX3V0aWxzLnB5) | `73.02% <0.00%> (+0.41%)` | :arrow_up: |

------

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> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/huggingface/transformers/pull/4025?src=pr&el=footer). Last update [2fade30...3a3c460](https://codecov.io/gh/huggingface/transformers/pull/4025?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
<|||||>Perfekt, vielen Dank haha :-) 