segmentation fault when execute API/reset multiple times and then call get API/schema

Hi Team

I use latest code and execute curl API multiple times.
```
curl -X POST localhost:8000/API/reset
```

Then, execute 
```
curl localhost:8000/API/schema
```

Then, got the error with process exit.

```
[1]    26064 segmentation fault  env MODE=READ_ONLY  npm run serve-prod
````

I think it might be related to this.connectionPool in Database.js