Bump lodash from 4.17.11 to 4.17.21 in /ait/gui/static

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.11 to 4.17.21.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.11...4.17.21)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

ait/gui/static/package-lock.json

@@ -25,7 +25,7 @@
     "jquery": "^3.2.1",
     "jsdom": "^9.11.0",
     "jsdom-global": "^2.1.1",
-    "lodash": "^4.17.11",
+    "lodash": "^4.17.21",
     "mithril": "^1.1.0",
     "mithril-query": "2.2.0",
     "mocha": "^3.1.2",