Keptn 0.12.1

This is a bug fix release for Keptn 0.12.0, containing fixes for the Keptn core services and the helm chart installer.

Bug Fixes

• Adapt HTTP status code for not found upstream repositories (#6872) (51e5855)
• Avoid nil pointer access for undefined value in helm charts (#6869) (96bc287)
• configuration-service: Ensure that git user and email are set before committing (#6871) (163af96)
• installer: External connection string not used while helm upgrade (#6870) (918fd83)