[Integrated] RFR: git-pr: git diff can exit with code 141

[Erik Helin]

Changeset: c73064e6
Author:    Erik Helin <ehelin at openjdk.org>
Date:      2020-02-07 15:07:59 +0000
URL:       https://git.openjdk.java.net/skara/commit/c73064e6

git-pr: git diff can exit with code 141

Reviewed-by: rwestberg

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