That is what your client 38.107.179.207:41809 (no PTR) sent:

,------
| GET / HTTP/1.1
| x-cc-id: ccc01-01
| Host: mirror.schlittermann.de
| User-Agent: CCBot/1.0 (+http://www.commoncrawl.org/bot.html)
| Accept: text/html,application/xhtml+xml,text/xml;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
| Accept-Language: en-us,en;q=0.5
| Accept-Encoding: gzip
| Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
| Connection: close
| Cache-Control: no-cache
| Pragma: no-cache
`------