Drop trailing slash (https://github.com/fluxcd/flux/issues/1852)

Chart.yaml

@@ -6,7 +6,7 @@ version: 0.2.4
 dependencies:
   - name: nextcloud
     version: 1.10.1
-    repository: https://nextcloud.github.io/helm/
+    repository: https://nextcloud.github.io/helm
   - name: rabbitmq
     version: 6.18.2
     repository: https://charts.bitnami.com/bitnami