PITR fails if max_connections has been increased

1. Create a db
2. Run `fly pg config update --max-connections 320`
3. Enable backups with `fly pg backups enable`
4. Restore from backup with `fly pg backups restore new-db`
5. The new DB fails to become healthy, and I don't think postgres ever exits recovery mode:
```
2024-08-12T19:55:42Z app[3d8dd719a93e78] iad [info]postgres | 2024-08-12 19:55:42.084 UTC [393] FATAL: recovery aborted because of insufficient parameter settings
2024-08-12T19:55:42Z app[3d8dd719a93e78] iad [info]postgres | 2024-08-12 19:55:42.084 UTC [393] DETAIL: max_connections = 300 is a lower setting than on the primary server, where its value was 320.
```