Fix detection whether Gluon version has already been forked

update-gluon.sh

@@ -21,7 +21,7 @@ git remote add upstream "$gluon_upstream_git_url"
 git fetch upstream --tags
 
 # we already have this branch - exit
-if ! git rev-parse --verify "$fork_newest_minor_branch" &> /dev/null; then
+if ! git rev-parse --verify "remotes/origin/$fork_newest_minor_branch" &> /dev/null; then
     echo "Nothing todo, branch $fork_newest_minor_branch already exists"
     exit 0
 fi