Fixed retain cycle in RCTFBHTTPRequestHandler
Fixed retain cycle in RCTFBHTTPRequestHandler

Summary: Following common ObjC pattern, we have to store delegates as weak pointers.

Reviewed By: mmmulani

Differential Revision: D6558886

fbshipit-source-id: 11a710a7e9e17d7c6a78ae46b53b043f44ccf8e5

myntra/react-native,rickbeerendonk/react-native,pandiaraj44/react-native,facebook/react-native,javache/react-native,myntra/react-native,jevakallio/react-native,javache/react-native,hoastoolshop/react-native,jevakallio/react-native,hoangpham95/react-native,exponent/react-native,arthuralee/react-native,hoastoolshop/react-native,jevakallio/react-native,javache/react-native,hoastoolshop/react-native,dikaiosune/react-native,facebook/react-native,javache/react-native,hammerandchisel/react-native,janicduplessis/react-native,Bhullnatik/react-native,pandiaraj44/react-native,jevakallio/react-native,exponentjs/react-native,Bhullnatik/react-native,pandiaraj44/react-native,rickbeerendonk/react-native,Bhullnatik/react-native,rickbeerendonk/react-native,ptmt/react-native-macos,ptmt/react-native-macos,dikaiosune/react-native,exponentjs/react-native,myntra/react-native,hoangpham95/react-native,exponent/react-native,hoangpham95/react-native,Bhullnatik/react-native,Bhullnatik/react-native,hammerandchisel/react-native,janicduplessis/react-native,rickbeerendonk/react-native,Bhullnatik/react-native,ptmt/react-native-macos,hoangpham95/react-native,ptmt/react-native-macos,exponentjs/react-native,hammerandchisel/react-native,dikaiosune/react-native,hoangpham95/react-native,jevakallio/react-native,arthuralee/react-native,hammerandchisel/react-native,rickbeerendonk/react-native,facebook/react-native,ptmt/react-native-macos,arthuralee/react-native,jevakallio/react-native,myntra/react-native,facebook/react-native,jevakallio/react-native,javache/react-native,myntra/react-native,exponentjs/react-native,pandiaraj44/react-native,dikaiosune/react-native,janicduplessis/react-native,javache/react-native,janicduplessis/react-native,Bhullnatik/react-native,facebook/react-native,facebook/react-native,janicduplessis/react-native,javache/react-native,dikaiosune/react-native,exponent/react-native,exponent/react-native,dikaiosune/react-native,ptmt/react-native-macos,hammerandchisel/react-native,pandiaraj44/react-native,javache/react-native,hoastoolshop/react-native,pandiaraj44/react-native,exponent/react-native,Bhullnatik/react-native,hoangpham95/react-native,rickbeerendonk/react-native,exponent/react-native,hammerandchisel/react-native,myntra/react-native,exponentjs/react-native,hoastoolshop/react-native,janicduplessis/react-native,pandiaraj44/react-native,facebook/react-native,hoastoolshop/react-native,janicduplessis/react-native,dikaiosune/react-native,myntra/react-native,dikaiosune/react-native,facebook/react-native,pandiaraj44/react-native,facebook/react-native,rickbeerendonk/react-native,exponentjs/react-native,janicduplessis/react-native,ptmt/react-native-macos,hoangpham95/react-native,myntra/react-native,hoangpham95/react-native,arthuralee/react-native,exponent/react-native,arthuralee/react-native,rickbeerendonk/react-native,exponentjs/react-native,rickbeerendonk/react-native,ptmt/react-native-macos,hammerandchisel/react-native,exponentjs/react-native,myntra/react-native,hoastoolshop/react-native,javache/react-native,hammerandchisel/react-native,hoastoolshop/react-native,jevakallio/react-native,exponent/react-native,jevakallio/react-native