Fix for array to string conversion Twig exception

This fixes the problem discussed in #83 where a Twig runtime exception is thrown when one of the job arguments is an array (which is always the case with jobs which support a retry strategy). 

More here: https://github.com/michelsalib/BCCResqueBundle/issues/83
Update index.html.twig
Merge pull request #91 from epicwhale/patch-1

Fix for array to string conversion Twig exception