fix link for icon

kubernetes/helm/Chart.yaml

@@ -2,4 +2,4 @@ apiVersion: v2
 name: open-webui
 description: "open-webui UI: A User-Friendly Web Interface for Chat Interactions 👋"
 version: 1.0.0
-icon: https://github.com/open-webui/open-webui/blob/main/static/favicon.png
+icon: https://raw.githubusercontent.com/open-webui/open-webui/main/static/favicon.png