Load locale settings instead of hardcoding them

Closes #3477277

core/includes/install.core.inc

@@ -249,7 +249,7 @@ function install_state_defaults() {
     // The server URL where the interface translation files can be downloaded.
     // Tokens in the pattern will be replaced by appropriate values for the
     // required translation file.
-    'server_pattern' => 'https://ftp.drupal.org/files/translations/%core/%project/%project-%version.%language.po',
+    'server_pattern' => \Drupal::TRANSLATION_DEFAULT_SERVER_PATTERN,
     // Installation tasks can set this to TRUE to force the page request to
     // end (even if there is no themeable output), in the case of an interactive
     // installation. This is needed only rarely; for example, it would be used