Comment 3 for bug 946776

This code and the hard-coded value 1 are related to:

17a: The tool should set innodb_lock_wait_timeout=1 automatically to avoid blocking other queries if it is blocked itself. (https://blueprints.launchpad.net/percona-toolkit/+spec/redesign-pt-table-checkum)

Iirc, the original ideas was to always set lock_wait_timeout=1 regardless of the server, but I snuck in the --lock-wait-timeout option and this code to make it configurable primarily because this var is only dynamic with the InnoDB plugin and I needed to change it for testing (to avoid warnings), but it looks like I implemented the option too specifically for my own needs. Therefore, yes, I'll fix it to make it sane for the user.