Sidenav destroy will reenable body scrolling

Author: Dogfalo

js/sidenav.js

@@ -95,6 +95,7 @@
      */
     destroy() {
       this._removeEventHandlers();
+      this._enableBodyScrolling();
       this._overlay.parentNode.removeChild(this._overlay);
       this.dragTarget.parentNode.removeChild(this.dragTarget);
       this.el.M_Sidenav = undefined;