Bug 41363: Fix error message about $update_responses_repository_dir being undefined

tools/signing/functions

@@ -23,7 +23,7 @@ function check_update_responses_repository_dir {
   if test -z "$update_responses_repository_dir" || ! test -d "$update_responses_repository_dir"
   then
     cat << 'EOF' > /dev/stderr
-$aus1_repository_dir is not defined, or the directory does not exist
+$update_responses_repository_dir is not defined, or the directory does not exist
 You should clone git@gitlab.torproject.org:tpo/applications/tor-browser-update-responses.git
 and set $update_responses_repository_dir in set-config.update-responses
 EOF