Remove auto-generation and default values for MySQL database.server.id

For MGDCTRS-904, we need to use the new Debezium 2.0 description for the MySQL database.server.id field when generating the schema from the 1.9 branch and we should also remove the fact the field has a default value from the schema generation as well.

In Debezium 2.0 this will automatically be handled by reading the field metadata.