Merge forwardport of #12633 to 2.3-develop branch

Applied pull request patch https://github.com/magento/magento2/pull/12633.patch (created by @miguelbalparda) based on commit(s):
  1. ef1ffd5
  2. cef5991

Fixed GitHub Issues in 2.3-develop branch:
  - #12632: Magento Connect no longer exist (reported by @miguelbalparda)

app/code/Magento/Marketplace/view/adminhtml/templates/index.phtml

@@ -46,9 +46,9 @@
         </div>
         <div class="col-m-3">
             <img
-                class="magento-connect-logo"
+                class="magento-marketplace-logo"
                 src="<?php /* @escapeNotVerified */ echo $block
-                    ->getViewFileUrl('Magento_Marketplace::partners/images/magento-connect.png');
+                    ->getViewFileUrl('Magento_Marketplace::partners/images/magento-marketplace.svg');
                 ?>"
                 alt="Partner"/>
         </div>
@@ -61,7 +61,7 @@
                 ); ?>
             </p>
             <a class="action-secondary" target="_blank"
-               href="http://www.magentocommerce.com/magento-connect/">
+               href="https://marketplace.magento.com/">
                 <?= /* @escapeNotVerified */ __('Visit Magento Marketplaces') ?>
             </a>
         </div>

app/design/adminhtml/Magento/backend/Magento_Marketplace/web/css/source/_module.less

@@ -61,7 +61,7 @@
 }
 
 .partners-footer {
-    .magento-connect-logo {
+    .magento-marketplace-logo {
         float: right;
         margin-bottom: 1px;
     }