make LOADABLE_MARKS private

Author: theKashey

src/marks.js

@@ -36,6 +36,4 @@ export const rehydrateMarks = (marks = false) => {
 
 export const printDrainHydrateMarks = (stream = 0) => {
   return `<script>window.___REACT_DEFERRED_COMPONENT_MARKS=${JSON.stringify(drainHydrateMarks(stream))};/*stream ${stream}*/</script>`;
-};
-
-export default LOADABLE_MARKS;
+};