Wrong redirect_uri in OAuth request causes 500 error

## Description

Wrong redirect_uri in OAuth request causes 500 error

---

## Where does this happen?
- [x] Official SUPLA Cloud (cloud.supla.org)
- [x] Self-hosted instance

---

## Expected behavior

It should display an informative error in SUPLA Cloud.

---

## Actual behavior

500

---

## Additional information (optional)

Logs, screenshots, notes, or anything else that may help.
