Update screenshots to match webui from go-ipfs 0.9.0

[lidel]

(filling so we dont forget)

https://github.com/ipfs/go-ipfs/releases/tag/v0.9.0 shipped and includes webui with support for remote pinning services.

Guide at https://docs.ipfs.io/how-to/work-with-pinning-services/#use-an-existing-pinning-service needs screenshot update:

• some labels and interfaces changed since then
  (eg. Secret API key got renamed to Secret access token)
• we only have Pinata at this time (other services are wip)