Remove PicApport (demo and documentation down, cannot find source cod…

…e) (#416)

- ref. #1 
- Demo server has been down for at least 2 weeks https://github.com/awesome-selfhosted/awesome-selfhosted-data/actions/runs/6950304970/job/18910184572
- Documentation server down as well https://wiki.picapport.de/display/PICE/License
- Cannot find actual source code