Update ngrok-operator version

[anmazzotti]

This issue is about reverting #1123
Chart version was pinned to v0.16.4, as the local dev environment was no longer working due to the new Cloud endpoint usage.

This results in Rancher endlessly returning a 302 with the same location.
Additionally there seem to be an issue with the Cloud endpoint. This one persists and on a second test cluster provisioning, it will still point to the previous (and now deleted) internal endpoint. (They have random names)
So it needs to be updated manually.