jenkins: do no longer remove the distro version file

as the distro version file is now also used in the nightly, it
will be overwritten and no longer be removed after a build.

BugzID: 69736

Signed-off-by: Marc Mattmueller <marc.mattmueller@netmodule.com>

Jenkinsfile

@@ -82,11 +82,6 @@ pipeline {
         }
         sh "rm -rf ${WORKSPACE}/tmp"
       }
-      post {
-        always {
-          cleanup_distro_version()
-        }
-      }
     }
   } // stages
 }