Fixes react native beta 5 break
Fixes react native beta 5 break

Summary: This fixes an error that shows up when building with Xcode 10 beta 5.

Reviewed By: fkgozali, dinhviethoa

Differential Revision: D9086574

fbshipit-source-id: 1d70049eafd20a85d482dca101980c71935d838e

arthuralee/react-native,exponent/react-native,facebook/react-native,exponent/react-native,javache/react-native,facebook/react-native,exponent/react-native,pandiaraj44/react-native,hammerandchisel/react-native,myntra/react-native,hammerandchisel/react-native,janicduplessis/react-native,myntra/react-native,hoangpham95/react-native,myntra/react-native,exponent/react-native,pandiaraj44/react-native,javache/react-native,exponent/react-native,janicduplessis/react-native,pandiaraj44/react-native,myntra/react-native,hammerandchisel/react-native,exponentjs/react-native,pandiaraj44/react-native,exponentjs/react-native,myntra/react-native,exponentjs/react-native,janicduplessis/react-native,pandiaraj44/react-native,pandiaraj44/react-native,hammerandchisel/react-native,myntra/react-native,arthuralee/react-native,hoangpham95/react-native,hammerandchisel/react-native,exponentjs/react-native,exponent/react-native,exponentjs/react-native,javache/react-native,javache/react-native,janicduplessis/react-native,janicduplessis/react-native,arthuralee/react-native,facebook/react-native,pandiaraj44/react-native,facebook/react-native,hoangpham95/react-native,myntra/react-native,pandiaraj44/react-native,arthuralee/react-native,hammerandchisel/react-native,javache/react-native,janicduplessis/react-native,janicduplessis/react-native,exponentjs/react-native,javache/react-native,exponent/react-native,myntra/react-native,hoangpham95/react-native,hoangpham95/react-native,hoangpham95/react-native,janicduplessis/react-native,hammerandchisel/react-native,facebook/react-native,arthuralee/react-native,hoangpham95/react-native,facebook/react-native,facebook/react-native,javache/react-native,javache/react-native,hoangpham95/react-native,hammerandchisel/react-native,exponentjs/react-native,facebook/react-native,facebook/react-native,myntra/react-native,exponent/react-native,javache/react-native,exponentjs/react-native