CB-6055 Fix mobile-spec trying to JSONify a FileEntry.
CB-6055 Fix mobile-spec trying to JSONify a FileEntry.

Used to be okay, but not anymore.

corimf/cordova-mobile-spec,polyvi/xface-mobile-spec,corimf/cordova-mobile-spec,ollie314/cordova-mobile-spec,apache/cordova-mobile-spec,corimf/cordova-mobile-spec,ollie314/cordova-mobile-spec,apache/cordova-mobile-spec,ollie314/cordova-mobile-spec,corimf/cordova-mobile-spec,polyvi/xface-mobile-spec,polyvi/xface-mobile-spec,ollie314/cordova-mobile-spec,apache/cordova-mobile-spec,ollie314/cordova-mobile-spec,corimf/cordova-mobile-spec,apache/cordova-mobile-spec,apache/cordova-mobile-spec