MAGETWO-43503: Currency symbol is displayed outside "Price" input on "create Downloadable Product" Admin page

- Add escape html

Author: Viktor Tymchynskyi

app/code/Magento/Downloadable/view/adminhtml/templates/product/edit/downloadable/links.phtml

@@ -109,7 +109,7 @@ require([
                 '<td class="col-price">'+
                     '<div class="admin__control-addon">' +
                         '<input type="text" id="downloadable_link_<%- data.id %>_price_value" class="input-text admin__control-text validate-number link-prices<?php if ($block->getCanEditPrice() === false) : ?> disabled<?php endif; ?>" name="downloadable[link][<%- data.id %>][price]" value="<%- data.price %>"<?php if ($block->getCanEditPrice() === false) : ?> disabled="disabled"<?php endif; ?> /> ' +
-                        '<label class="admin__addon-prefix"><span><?php /* @escapeNotVerified */ echo $block->getBaseCurrencySymbol($_product->getStoreId()) ?></span></label>' +
+                        '<label class="admin__addon-prefix"><span><?php echo $block->escapeHtml($block->getBaseCurrencySymbol($_product->getStoreId())) ?></span></label>' +
                     '</div>' +
                     <?php if ($_product->getStoreId() && $block->getIsPriceWebsiteScope()) : ?>
                         '<div class="admin__field admin__field-option">'+