Fix interaction event error using import wrappers

Fixes #74

Author: maoberlehner

src/utils/hydration-blocker.js

@@ -59,7 +59,7 @@ export function makeHydrationBlocker(component, options) {
           this.hydrationPromise.then(cleanup);
         }
 
-        if (this.interactionEvents.length) {
+        if (this.interactionEvents && this.interactionEvents.length) {
           const eventListenerOptions = {
             capture: true,
             once: true,