[usercase-wrt] update mutiuser testcase to designed

[Detailed commit message (if have)]
Impacted TCs num(designed): New 0, update 0, deleted 0
Unit test platform: [tizen]
Unit test result summary: only update tests.xml
Merge pull request #890 from linshen/shenlin/wrt-usecase-move-multiuser

[usercase-wrt] update mutiuser testcase to designed