reproducible: use correct git branch for building reprotest

Signed-off-by: Holger Levsen <holger@layer-acht.org>

job-cfg/reproducible.yaml

@@ -900,7 +900,7 @@
                     my_description: 'Build reprotest Debian package from git branch "debian"'
                     my_timed: '23 13 1 1 *'
                     my_gitrepo: 'https://salsa.debian.org/reproducible-builds/reprotest.git'
-                    my_gitbranches: 'origin/debian'
+                    my_gitbranches: 'origin/master'
                     my_shell: '/srv/jenkins/bin/chroot-run.sh sid debuild -uc -us -b'
                     my_parse_rules: '/srv/jenkins/logparse/debian-pkg-ci.rules'
                 - 'builds_website':