Change update stream to stable

[JUVOJustin]

It seems to me the cloudron updates currently follow the github releases without any further filtering. On all of my servers the pre-release version was automatically installed.

I would be very happy if the update stream could be changed to stable releases only.

One example: Current released version is 1.8.1 which contains a bug in the mysql node. It is already fixed in 1.8.2 and was not existing in 1.7.1. This issue could have been easily avoided by just installing the "latest" release.

[girish]

@JUVOJustin thanks for bringing this up. This was an oversight. We don't update to prereleases. We missed the pre-release tag on GitHub.

We are fixing releasebell accordingly.

[girish]

Releasebell is our release notification app.

[JUVOJustin]

Perfect, thank you very much