Issue #3386508 by Grimreaper: Add license URL to Bootstrap library

ui_suite_bootstrap.libraries.yml

@@ -2,6 +2,7 @@ bootstrap:
   remote: http://getbootstrap.com/
   license:
     name: MIT
+    url: https://github.com/twbs/bootstrap/blob/main/LICENSE
     gpl-compatible: false
   js:
     /libraries/bootstrap/dist/js/bootstrap.bundle.min.js: { minified: true }