Logout will not write new generated search index in this session

### Description

Logout will not write new generated search index in this session

### Steps to reproduce

It says my search index is around 400k (at the start of this login it's around 100kb)
Don't close program(or it will write the db)
Logout & login then you see the search db **go back** to 100k

Describe how what happens differs from what you expected.
Logout should write new genereated search index. But it's not.

Logs being sent: yes/no

### Version information

- **Platform**: web (in-browser) or desktop?

For the web app:

- **Browser**: Chrome, Firefox, Safari, Edge? which version?
- **OS**: Windows, macOS, Ubuntu, Arch Linux, etc?
- **URL**: develop.element.io / app.element.io / somewhere else? If a private server, what version of Element Web?

For the desktop app:

- **OS**: Windows, macOS, Ubuntu, Arch Linux, etc?
- win x64
- **Version**: 1.x.y
- 1.7.28