Fix error in dialog_controller.js by checking for event before calling preventDefault

Author: justinallenmarsh

lib/ruby_ui/dialog/dialog_controller.js

@@ -17,7 +17,9 @@ export default class extends Controller {
   }
 
   open(e) {
-    e.preventDefault()
+    if (e) {
+      e.preventDefault();
+    }
     document.body.insertAdjacentHTML('beforeend', this.contentTarget.innerHTML)
     // prevent scroll on body
     document.body.classList.add('overflow-hidden')