Fix tagged commit detection in the Jenkinsfile
Fix tagged commit detection in the Jenkinsfile

The previous check was causing false positives. It considered every
ancestor commit of a tag as being tagged. This caused the `develop`
branch to run release stages because it was an ancestor of the tagged
merge commit on `master`.

gini/gini-sdk-android,gini/gini-sdk-android,gini/gini-sdk-android