Make new item swap reversible

index.html

@@ -105,8 +105,7 @@
           <div><span>Regen change</span><strong id="replacementRegenDelta">0</strong></div>
         </div>
         <div class="swap-actions">
-          <button id="swapNewItem" type="button">Swap in new item</button>
-          <button id="swapBackNewItem" type="button" class="secondary" disabled>Swap back</button>
+          <button id="swapNewItem" type="button">Swap</button>
           <span id="swapStatus" class="status"></span>
         </div>
       </section>