This new CHANGE MASTER TO field specifies the `--master-retry-count`
(global option: the number of Primary connection attempts)
for each multi-source replica; i.e, per-channel `performance_schema.`
`replication_connection_configuration.connection_retry_count`.
`--master-retry-count` remains the default for new `CHANGE MASTER TO`s.
This new keyword and `master-info` format
matches those of pre-‘REPLICATION SOURCE’ MySQL.