Handle error returned by GetClusterInfos() (#30919)

A recent change to the enterprise cluster code introduced a change to the enterprise API interface. GetClusterInfos() can now return an error. This commit introduces code to handle that error.

server/channels/app/admin.go

@@ -131,14 +131,11 @@ func (a *App) GetLogsSkipSend(rctx request.CTX, page, perPage int, logFilter *mo
 	return a.Srv().GetLogsSkipSend(rctx, page, perPage, logFilter)
 }
 
-func (a *App) GetClusterStatus(rctx request.CTX) []*model.ClusterInfo {
-	infos := make([]*model.ClusterInfo, 0)
-
-	if a.Cluster() != nil {
-		infos = a.Cluster().GetClusterInfos()
+func (a *App) GetClusterStatus(rctx request.CTX) ([]*model.ClusterInfo, error) {
+	if a.Cluster() == nil {
+		return make([]*model.ClusterInfo, 0), nil
 	}
-
-	return infos
+	return a.Cluster().GetClusterInfos()
 }
 
 func (s *Server) InvalidateAllCaches() *model.AppError {