ENYO-3883: Make cache control test only special case iOS 6

Enyo-DCO-1.1-Signed-Off-By: Ben Combee (ben.combee@lge.com)
Merge pull request #682 from enyojs/ENYO-3883-unwiredben

ENYO-3883: Make cache control test only special case iOS 6

Reviewed-By: Cole Davis (cole.davis@lge.com)