Bump handlebars from 4.1.2 to 4.5.3

Bumps [handlebars](https://github.com/wycats/handlebars.js) from 4.1.2 to 4.5.3.
- [Release notes](https://github.com/wycats/handlebars.js/releases)
- [Changelog](https://github.com/wycats/handlebars.js/blob/master/release-notes.md)
- [Commits](https://github.com/wycats/handlebars.js/compare/v4.1.2...v4.5.3)

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -31,7 +31,7 @@
     "cors": "2.8.5",
     "express": "4.16.4",
     "glyph-pbf-composite": "0.0.2",
-    "handlebars": "4.1.2",
+    "handlebars": "4.5.3",
     "http-shutdown": "^1.2.0",
     "morgan": "1.9.1",
     "pbf": "3.1.0",