Validation of binlog_row_image is not compatible with MySQL 5.5

In DBZ-1340 a validation was added for binlog_row_image; however this option was only added as of MySQL 5.6 and this causes the connector to fail during startup for MySQL 5.5 environments.

We can probably get away with checking if the value is set and if so, verify the value is set to full; however since the default is full, it should be safe to assume if the value isn't set to allow the validation to succeed.