common: fix monitor logger unit test crash problem.
common: fix monitor logger unit test crash problem.

jinghaomiao/apollo,jinghaomiao/apollo,xiaoxq/apollo,jinghaomiao/apollo,jinghaomiao/apollo,ApolloAuto/apollo,ApolloAuto/apollo,ycool/apollo,wanglei828/apollo,wanglei828/apollo,wanglei828/apollo,xiaoxq/apollo,ycool/apollo,wanglei828/apollo,ycool/apollo,ApolloAuto/apollo,xiaoxq/apollo,ApolloAuto/apollo,ycool/apollo,ApolloAuto/apollo,ycool/apollo,wanglei828/apollo,xiaoxq/apollo,jinghaomiao/apollo,xiaoxq/apollo,jinghaomiao/apollo,ApolloAuto/apollo,ycool/apollo,wanglei828/apollo,xiaoxq/apollo