Update 06.2.md
Update 06.2.md

Fix a typo in "Session Manager" section.
astaxie/build-web-application-with-golang,WangKaimin/build-web-application-with-golang,faxriddin/build-web-application-with-golang,admpub/build-web-application-with-golang,astaxie/build-web-application-with-golang,songqii/build-web-application-with-golang,astaxie/build-web-application-with-golang,faxriddin/build-web-application-with-golang,songqii/build-web-application-with-golang,admpub/build-web-application-with-golang,WangKaimin/build-web-application-with-golang,admpub/build-web-application-with-golang,admpub/build-web-application-with-golang