[webapi] Remove invalid case for SSO

Impacted TCs num(approved): New 0, Update 0, Delete 1
Unit test Platform: [Tizen-IVI]
Unit test result summary: Pass 0, Fail 0, Blocked 0
Merge pull request #1117 from JianfengXu/SSO/invalid

[webapi][XWALK-2470] Remove invalid case for SSO