swh/web: Use a real endpoint as probe instead of a 301 redirect

swh/templates/web/deployment.yaml

@@ -122,7 +122,7 @@ spec:
               name: webapp
           readinessProbe:
             httpGet:
-              path: /api/1
+              path: /api/1/
               port: webapp
               httpHeaders:
                 - name: Host