Fix for an error with CakeResque

[iglocska]

• An array is passed to formatArgument() within Redisent.php, where an error is generated each time strlen() is run on the array
• Also mentioned in kamisama/Cake-Resque#30 by krazp
• This change simply checks whether the parameter is an array, if yes, it adds up the lengths of each value in the array
• If it doesn't get an array, it simply checks the length expecting a string

[wa0x6e]

Thanks.

[stw3]

We are experiencing the same issue as described by hdviet. We are currently using CakeResque 4.1.0. The error occurs only for the two methods (enqueueAt, enqueueIn) using the job scheduler.