<!--- Provide a general summary of your changes in the title. -->
## Description
This PR corrects the German lemma form for the word "Rang". Initially, the lemma form was "ringen", which is not correct, because it refers to the verb ("ringen") and not to the noun ("Rang").
### Types of change
The lemma form for "Rang" is corrected to "Rang", see also the [Duden](https://www.duden.de/rechtschreibung/Rang) entry.
## Checklist
<!--- Before you submit the PR, go over this checklist and make sure you can
tick off all the boxes. [] -> [x] -->
- [x] I have submitted the spaCy Contributor Agreement.
- [x] I ran the tests, and all new and existing tests passed.
- [x] My changes don't require a change to the documentation, or if they do, I've added all required information.
Renaming the tag with an underscore lets us add it to the tag map
without worrying that we'll change the sequence of tags, which throws
off the tag-to-ID mapping. For instance, if we inserted a 'SP' tag,
the "VERB" tag is pushed to a different class ID, and the model is all
messed up.
