Fix help.

github/download-github-release.sh

@@ -26,7 +26,7 @@ Options:
   -a ARTIFACT    the artifact to download, e.g. macos-notarization-service
   -e EXTENSION   the extension to use, default: .zip
   -r REPO        the GitHub repo to use for download, format: owner/repo-name, e.g. eclipse-cbi/macos-notarization-service
-  -v VERSION     the release version to download, e.g. v1.2.0
+  -v VERSION     the release version to download, e.g. 1.2.0
   -h             show this help
 
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