Fix build react-native ios 13 XCode 11.3.1

RCTModuleMethod.m

#node_modules/react-native/React/Base/RCTModuleMethod.mm

##and update below code

static BOOL RCTParseUnused(const char **input)
{
  return RCTReadString(input, "__attribute__((unused))") ||
           RCTReadString(input, "__attribute__((__unused__))") ||
           RCTReadString(input, "__unused");
}
##after doing that

##uninstall the old app from your real device

##rebuild the application! and this shall be gone!