Update concepts-pgbouncer.md

Add more explanation to `ignore_startup_parameters` from the doumentation of pgbouncer regarding the suggested value.

Author: trewallier

articles/postgresql/flexible-server/concepts-pgbouncer.md

@@ -34,7 +34,7 @@ You can configure PgBouncer, settings with these parameters:
 | pgBouncer.max_client_conn | Set this parameter value to the highest number of client connections to PgBouncer that you want to support .     | 5000     | 
 | pgBouncer.pool_mode | Set this parameter value to TRANSACTION for transaction pooling (which is the recommended setting for most workloads).      | TRANSACTION     |
 | pgBouncer.min_pool_size | Add more server connections to pool if below this number.    |   0 (Disabled)   |
-| pgbouncer.ignore_startup_parameters | Comma-separated list of parameters that PgBouncer can ignore. For example, you can let PgBouncer ignore `extra_float_digits` parameter.|   |
+| pgbouncer.ignore_startup_parameters | Comma-separated list of parameters that PgBouncer can ignore. For example, you can let PgBouncer ignore `extra_float_digits` parameter. New config var 'ignore_startup_parameters' to allow and ignore extra parameters in startup packet. By default only 'database' and 'user' are allowed, all others raise error. This is needed to tolerate overenthusiastic JDBC wanting to unconditionally set 'extra_float_digits=2' in startup packet. |   |
 | pgbouncer.query_wait_timeout | Maximum time (in seconds) queries are allowed to spend waiting for execution. If the query is not assigned to a server during that time, the client is disconnected. | 120s |
 | pgBouncer.stats_users | Optional. Set this parameter value to the name of an existing user, to be able to log in to the special PgBouncer statistics database (named “PgBouncer”).    |      |