* 🐛 debug grpc export (#2379) #2379 Fixed the issue that the GRPC exporter did not establish an RPC link 原文使用的 otlptracegrpc.NewUnstarted创建的是一个未建立rpc连接的导出器，无法正常使用；改为otlptracegrpc.New才妥 * Update agent_test.go 修复单元测试失败
Co-authored-by: Gene Wu <gene.wu@cabital.com>
* feat: support multiple trace agents * feat: support multiple trace agents, let later calls run if error happens * test: add more tests
