使用c++sdk接入，在北极星服务端发版时，会产生core dump

[jobop]

c++ sdk版本：1.1.2
服务端版本：1.13
北极星节点连接拓扑： c++ sdk -> vip ->后端北极星服务

问题产生过程：发布北极星服务端时，重启了一批节点，更换了一些节点ip。客户端此时发送core dump。

客户端报错信息：

warning: Ignoring non-absolute filename: <./lib64_release/libiomp5.so>
Missing separate debuginfo for ./lib64_release/libiomp5.so
Try: yum --enablerepo='debug' install /usr/lib/debug/.build-id/9d/fa23ad70f3f8f50699aac84586f3ba832b7034.debug
Core was generated by `bin/recall_server --flagfile=conf/theme.gflags'.
Program terminated with signal 11, Segmentation fault.
#0 _M_get (this=) at thirdparty/polaris-cpp/polaris/model/instance.cpp:43
43 thirdparty/polaris-cpp/polaris/model/instance.cpp: No such file or directory.
Missing separate debuginfos, use: debuginfo-install blas-3.4.2-8.el7.x86_64 glibc-2.17-292.el7.x86_64 keyutils-libs-1.5.8-3.el7.x86_64 krb5-libs-1.15.1-37.el7_7.2.x86_64 lapack-3.4.2-8.el7.x86_64 libcom_err-1.42.9-16.el7.x86_64 libgcc-4.8.5-39.el7.x86_64 libgfortran-4.8.5-39.el7.x86_64 libgomp-4.8.5-39.el7.x86_64 libquadmath-4.8.5-39.el7.x86_64 libselinux-2.5-14.1.el7.x86_64 libstdc++-4.8.5-36.el7.x86_64 pcre-8.32-17.el7.x86_64
(gdb) bt
#0 _M_get (this=) at thirdparty/polaris-cpp/polaris/model/instance.cpp:43
#1 operator-> (this=) at /opt/rh/devtoolset-8/root/usr/include/c++/8/bits/shared_ptr_base.h:1013
#2 polaris::Instance::GetPort (this=0x0) at thirdparty/polaris-cpp/polaris/model/instance.cpp:43
#3 0x00000000007eb727 in polaris::BlockRequest::OnFailure(std::string const&) ()
at thirdparty/polaris-cpp/polaris/plugin/server_connector/grpc_server_connector.cpp:937
#4 0x00000000007b6b54 in polaris::grpc::Http2Client::ResetAllStream (this=this@entry=0x7f9ba9f0e100,
status=status@entry=polaris::grpc::kGrpcStatusAborted, message="read from socket fd failed")
at thirdparty/polaris-cpp/polaris/network/grpc/http2.cpp:934
#5 0x00000000007b76dd in polaris::grpc::Http2Client::ReadHandler() () at thirdparty/polaris-cpp/polaris/network/grpc/http2.cpp:654
#6 0x000000000078978c in polaris::Reactor::RunEpollTask (this=this@entry=0x7fa780a0bd40, timeout=)
at thirdparty/polaris-cpp/polaris/reactor/reactor.cpp:180
#7 0x0000000000789973 in polaris::Reactor::Run (this=this@entry=0x7fa780a0bd40) at thirdparty/polaris-cpp/polaris/reactor/reactor.cpp:207
#8 0x00000000007edd7a in polaris::GrpcServerConnector::ThreadFunction (arg=0x7fa780a0bd00)
at thirdparty/polaris-cpp/polaris/plugin/server_connector/grpc_server_connector.cpp:250
#9 0x00007fa7ce674e65 in start_thread () from /lib64/libpthread.so.0
#10 0x00007fa7832d688d in clone () from /lib64/libc.so.6