CORE-2223 update react native SDK version

Author: echo-branch

react-native-branch.podspec

@@ -22,6 +22,6 @@ Pod::Spec.new do |s|
   s.source_files = [ "ios/*.h", "ios/*.m"]
   s.compiler_flags = %[-DRNBRANCH_VERSION=@\\"#{s.version}\\"]
   s.header_dir   = 'RNBranch' # also sets generated module name
-  s.dependency 'Branch', '1.39.3'
+  s.dependency 'Branch', '1.39.4'
   s.dependency 'React' # to ensure the correct build order
 end