Remove dead private methods
Remove dead private methods

Summary: There is one private method in IGListKit which isn't being called from anywhere. We should just remove it.

Reviewed By: rnystrom

Differential Revision: D8346790

fbshipit-source-id: b74766373ca6b9262e03c728b26b647e164fcb03

Instagram/IGListKit,zhubofei/IGListKit,Instagram/IGListKit,zhubofei/IGListKit,Instagram/IGListKit,zhubofei/IGListKit,Instagram/IGListKit,zhubofei/IGListKit,zhubofei/IGListKit,Instagram/IGListKit