Nominatim is down when a lot of data comes.

From slack channel, with @1ec5 @batpad 

`Nominatim is down. Might be all the new boundaries Nominatim has to deal `

```
'Failed to establish database connection:SQLSTATE[08006] [7] connection to server on socket "/var/run/postgresql/.s.PGSQL.5432" failed: FATAL: sorry, too many clients already'
```

One possible solution it to configure nominatim-postgres to accept more connection. 
 