fix exception when get kube stdout
fix exception when get kube stdout

shyamjvs/perf-tests,shyamjvs/perf-tests,kubernetes/perf-tests,kubernetes/perf-tests,shyamjvs/perf-tests,kubernetes/perf-tests,kubernetes/perf-tests,kubernetes/perf-tests,shyamjvs/perf-tests,shyamjvs/perf-tests