[ivi-tct][webapi][XWALK-3212] Remove this w3c test including idlharness

- Remove w3c mediastreamtrack-init-manual.html, since this is idlharness test
Merge pull request #1529 from xinliux/gumallow/XWALK-3212

[ivi-tct][webapi][XWALK-3212] Remove this w3c test including idlharness