SCRIPTS: update create-release to fix the changelog on new branches

The changelog is empty when creating a dev0 version and this confuses
the commit message, let's clearly mention the exact copy when there are
no changes.
diff --git a/scripts/create-release b/scripts/create-release
index fe6c802..8a8e05d 100755
--- a/scripts/create-release
+++ b/scripts/create-release
@@ -164,7 +164,11 @@
   echo
   echo "$DATE : $NEW"
   #git shortlog v$OLD.. | sed -ne 's/^      /    - /p'
-  git log --oneline --reverse --format="    - %s" v$OLD..
+  if [ $(git log --oneline v$OLD.. | wc -l) = 0 ]; then
+    echo "    - exact copy of $OLD"
+  else
+    git log --oneline --reverse --format="    - %s" v$OLD..
+  fi
   echo
   tail -n +4 CHANGELOG
 ) >.chglog.tmp && mv .chglog.tmp CHANGELOG