WL#4965: Change default of InnoDB Thread Concurrency to 0

Changed default of InnoDB Thread Concurrency to 0.
In MySQL 5.4.0

In MySQL 5.4.0, change the default of innodb_thread_concurrency from 8 to 0. In
effect, this changes concurrency from 8 to “infinite”. 


This change is made to provide better “out of box” configuration of default 
values for MySQL operation on up to 16-way x86 servers and 64-way CMT servers
with 4GB or more memory.

Default value of an existing variable changed; no
further LLD required.