fix: totp unlink image in 2fa docs

[MiniDigger]

Related issue(s)

none

Checklist

• I have read the contributing guidelines.
• I have referenced an issue containing the design document if my change
  introduces a new feature.
• I am following the
  contributing code guidelines.
• I have read the security policy.
• I confirm that this pull request does not address a security
  vulnerability. If this pull request addresses a security. vulnerability, I
  confirm that I got green light (please contact
  security@ory.sh) from the maintainers to push
  the changes.
• I have added tests that prove my fix is effective or that my feature
  works.
• I have added or changed the documentation.

Further Comments

just found this while implementing totp into my app (which was surprisingly easy, thanks for that!)

[CLAassistant]

All committers have signed the CLA.

[MiniDigger]

ngl, signing a cla for a one char change is really funny 😂

[aeneasr]

😅 yeah sorry, the CLA bot does not yet distinguish between significant changes and not significant changes :/