Update dependency knex to v2 [SECURITY]

Author: renovate[bot]

package.json

@@ -38,7 +38,7 @@
     "express-session": "1.17.2",
     "express-validator": "6.13.0",
     "ics": "2.31.0",
-    "knex": "0.21.21",
+    "knex": "2.4.0",
     "lusca": "1.7.0",
     "markdown-it": "12.3.2",
     "multer": "1.4.3",