[issue-868]: Deleting multiple blocks triggers back button in Firefox (#967)

* Deleting multiple blocks triggers back button in Firefox

@evgenusov

* Update editor.js

* Update CHANGELOG.md

docs/CHANGELOG.md

@@ -11,6 +11,7 @@
 — `Fix` — Fix flipper with empty dom iterator [#926](https://github.com/codex-team/editor.js/issues/926)
 - `Fix` — Normalize node before walking through children at `isEmpty` method [943](https://github.com/codex-team/editor.js/issues/943)
 — `Fix` — Fixed Grammarly conflict [#779](https://github.com/codex-team/editor.js/issues/779)
+— `Fix` — Fixed History Back on block deletion by Backspace in Firefox [#967](https://github.com/codex-team/editor.js/pull/967)
 
 ### 2.15.1
 

src/components/modules/ui.ts

@@ -402,6 +402,7 @@ export default class UI extends Module {
        * Manipulation with BlockSelections is handled in global backspacePress because they may occur
        * with CMD+A or RectangleSelection and they can be handled on document event
        */
+      event.preventDefault();
       event.stopPropagation();
       event.stopImmediatePropagation();
     }