MAGETWO-69080: [Backport] - [Magento Cloud] - After updating quantity of item in basket, original item quantity is being held in the quantity field on the update item page - for 2.1

Author: iivashchenko

app/code/Magento/Checkout/view/frontend/templates/cart/item/configure/updatecart.phtml

@@ -15,18 +15,20 @@
         <fieldset class="fieldset">
             <?php if ($block->shouldRenderQuantity()): ?>
             <div class="field qty">
-                <label class="label" for="qty"><span><?php /* @escapeNotVerified */ echo __('Qty') ?></span></label>
+                <label class="label" for="qty"><span><?php echo $block->escapeHtml(__('Qty')); ?></span></label>
                 <div class="control">
-                    <input type="number" name="qty" id="qty" maxlength="12" value="" title="<?php /* @escapeNotVerified */ echo __('Qty') ?>" class="input-text qty" data-validate="{'required-number':true,digits:true}"/>
+                    <input type="number" name="qty" id="qty" maxlength="12" value=""
+                           title="<?php echo $block->escapeHtml(__('Qty')); ?>"
+                           class="input-text qty" data-validate="{'required-number':true,digits:true}"/>
                 </div>
             </div>
             <?php endif; ?>
             <div class="actions">
                 <button type="submit"
-                        title="<?php /* @escapeNotVerified */ echo $buttonTitle ?>"
+                        title="<?php echo $block->escapeHtml($buttonTitle); ?>"
                         class="action primary tocart"
                         id="product-updatecart-button">
-                    <span><?php /* @escapeNotVerified */ echo $buttonTitle ?></span>
+                    <span><?php echo $block->escapeHtml($buttonTitle); ?></span>
                 </button>
                 <?php echo $block->getChildHtml('', true) ?>
             </div>