Revert "client npm upgrade: bump typescript from 3.3.1 to 3.9.10 in /client"

Author: mirkan1

client/package-lock.json

@@ -213,7 +213,7 @@
     "tslint-eslint-rules": "^5.4.0",
     "tslint-no-focused-test": "^0.5.0",
     "tslint-react": "^5.0.0",
-    "typescript": "^3.9.10",
+    "typescript": "^3.3.1",
     "url-loader": "^1.1.2",
     "webpack": "^4.20.2",
     "webpack-build-notifier": "^0.1.30",