[hackers] [scroll] Fix GNU getop || Jochen Sprickerhof

[git]

commit a0db4efd2e01b0458fe1f0724bff0b4cfc42c35c
Author:     Jochen Sprickerhof <g...@jochen.sprickerhof.de>
AuthorDate: Fri Apr 24 00:15:54 2020 +0200
Commit:     Jochen Sprickerhof <g...@jochen.sprickerhof.de>
CommitDate: Fri Apr 24 00:15:54 2020 +0200

    Fix GNU getop

diff --git a/up.sh b/up.sh
index 95ae93c..a730f8c 100755
--- a/up.sh
+++ b/up.sh
@@ -1,6 +1,7 @@
 #!/bin/sh
 
 set -eu
+export POSIXLY_CORRECT=1
 
 jot 50 > tmp.log