[wrt][XWALK-890]update test.py fix run fail issure

Detailed commit message]
Impacted TCs num(approved): New 0, update 0, deleted 0
Unit test platform: [tizen]
fix run fail case but no update result issure
Merge pull request #447 from linshen/update-wrt-manifest-tizen-tests

[wrt][XWALK-890]update test.py fix run fail issure