[Integrated] RFR: git-webrev: add support for "upstream" remote

[Erik Helin]

Changeset: 4b59403a
Author:    Erik Helin <ehelin at openjdk.org>
Date:      2019-12-09 14:49:15 +0000
URL:       https://git.openjdk.java.net/skara/commit/4b59403a

git-webrev: add support for "upstream" remote

Reviewed-by: rwestberg

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