fix libre-graph status codes (#7705)

* fix libre-graph status codes

* owncloud-test-middleware bumped

---------

Co-authored-by: Roman Perekhod <rperekhod@owncloud.com>

services/graph/pkg/service/v0/groups.go

@@ -97,7 +97,7 @@ func (g Graph) PostGroup(w http.ResponseWriter, r *http.Request) {
 		}
 		g.publishEvent(r.Context(), e)
 	}
-	render.Status(r, http.StatusOK) // FIXME 201 should return 201 created
+	render.Status(r, http.StatusCreated)
 	render.JSON(w, r, grp)
 }