MAGETWO-85180: [Backport 2.1-develop] Fix swagger-ui on instances of Magento running on a non-standard port #12579

 - Merge Pull Request #12579 from JeroenVanLeusden/magento2:patch-3
 - Merged commits:
   1. bfbd9be

Author: ishakhsuvarov

app/code/Magento/Webapi/Controller/Rest.php

@@ -280,7 +280,7 @@ protected function processSchemaRequest()
         $responseBody = $this->swaggerGenerator->generate(
             $requestedServices,
             $this->_request->getScheme(),
-            $this->_request->getHttpHost(),
+            $this->_request->getHttpHost(false),
             $this->_request->getRequestUri()
         );
         $this->_response->setBody($responseBody)->setHeader('Content-Type', 'application/json');