fix(apps): remove non-link sources (#6826)

charts/stable/kanboard/Chart.yaml

@@ -2,7 +2,7 @@ apiVersion: v2
 appVersion: "1.2.26"
 description: Kanboard is a free and open source Kanban project management software.
 name: kanboard
-version: 11.0.20
+version: 11.0.21
 kubeVersion: ">=1.16.0-0"
 keywords:
   - kanboard
@@ -12,7 +12,6 @@ icon: https://truecharts.org/img/hotlink-ok/chart-icons/kanboard.png
 sources:
   - https://github.com/truecharts/charts/tree/master/charts/stable/kanboard
   - https://hub.docker.com/kanboard/kanboard
-  - kanboard/kanboard
   - https://github.com/kanboard/kanboard
 dependencies:
   - name: common