Backport #19048
There is (yet) another problem with v210 in that Postgres will silently allow preset
ID insertions ... but it will not update the sequence value.
This PR simply adds a little step to the end of the v210 migration to update the
sequence number.
Users who have already migrated who find that they cannot insert new
webauthn_credentials into the DB can either run:
```bash
gitea doctor recreate-table webauthn_credential
```
or
```bash
SELECT setval('webauthn_credential_id_seq', COALESCE((SELECT MAX(id)+1 FROM `webauthn_credential`), 1), false)
```
which will fix the bad sequence.
Fix#19012
Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: 6543 <6543@obermui.de>
d285905826