PITR fails if max_connections has been increased

[benwaffle]

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.