[Integrated] RFR: git-pr: use upstream remote if available

[Erik Helin]

Changeset: adf1bcb7
Author:    Erik Helin <ehelin at openjdk.org>
Date:      2019-12-05 13:23:34 +0000
URL:       https://git.openjdk.java.net/skara/commit/adf1bcb7

git-pr: use upstream remote if available

Reviewed-by: rwestberg

! cli/src/main/java/org/openjdk/skara/cli/GitPr.java