Changelog isn't published to nextcloud app store

[Vrumf0ndel]

The CHANGELOG.md format is slightly different to what the parser expects for importing the changelog to nextcloud app store.

Related to description following syntax is needed:

The regex for matching the line is ^## (\d+.\d+.\d+)

Replacing ### 1.0.6 by ## 1.0.6 should fix this issue.

E.g.

# Changelog
## 1.0.6
### Fixed
- composer php7.3