fix(deps): update dependency sequelize to v5.21.4

Author: renovate-bot

sample/07-sequelize/package-lock.json

@@ -26,7 +26,7 @@
     "reflect-metadata": "0.1.13",
     "rimraf": "3.0.1",
     "rxjs": "6.5.4",
-    "sequelize": "5.21.3",
+    "sequelize": "5.21.4",
     "sequelize-typescript": "1.1.0",
     "typescript": "3.7.2"
   },