Fix Links

From https://codebase.helmholtz.cloud/hifis/overall/hifis-technical-documentation/-/jobs/1208737/raw

• https://login-dev.helmholtz.de/unitygw/VAADIN/files/connected-services.html (HTTP_404)
• https://indigo-dc.gitbook.io/oidc-agent/installation (HTTP_404)
• https://plony.helmholtz.cloud/static_files/documents/plony_instruction.pdf/@@download/file (HTTP_404)
• https://webfts.cern.ch/ (BLC_UNKNOWN)
• https://nubes.helmholtz-berlin.de/s/o3f4sN3bpD5oDLm/download (BLC_UNKNOWN)
• https://hifis-cloud-portal.desy.de/ (ERRNO_ENOTFOUND)
• https://www.stab.kit.edu/downloads/201310_IuK_Ordnung_engl.pdf (ERRNO_ENOTFOUND)
• https://rclone.org/downloads (HTTP_308)
• https://indigo-dc.gitbook.io/oidc-agent/installation (HTTP_404)
• Multiple Error: Expected type "text/html" but got "application/vnd.openxmlformats-officedocument.presentationml.presentation"