Confirmation Email error

### How to reproduce these conditions

**Sample name or URL where you found the bug**

Confirmation Email

**Failing Function code used (including require/import commands at the top)**

functions/index.js

**Steps to set up and reproduce**

**Sample data pasted or attached as JSON (not an image)**

**Security rules used**

### Debug output

**Errors in the [console logs](https://console.firebase.google.com/project/_/functions/logs?search=&severity=DEBUG)**

TypeError: snapshot.changed is not a function
at exports.sendEmailConfirmation.functions.database.ref.onWrite (/srv/index.js:38:17)
at cloudFunctionNewSignature (/srv/node_modules/firebase-functions/lib/cloud-functions.js:105:23)
at /worker/worker.js:804:24
at
at process._tickDomainCallback (internal/process/next_tick.js:229:7)

**Screenshots**

### Expected behavior

### Actual behavior