chore(deps): update dependency rxjs to v6.6.6

Author: renovate-bot

package-lock.json

@@ -40,7 +40,7 @@
     "prettier": "2.2.1",
     "reflect-metadata": "0.1.13",
     "release-it": "14.4.1",
-    "rxjs": "6.6.3",
+    "rxjs": "6.6.6",
     "rxjs-compat": "6.6.3",
     "supertest": "6.1.3",
     "ts-jest": "26.5.2",