Create new qml application and add to version control Mercurial, project can be created but not loaded to project manager

Reproduction steps:

1. Create a QtQuick UI Application using wizard
2. Follow the whole steps until the last one
3. During the step - Add to version control, select the item "Mercurial"
4. Click finish

Expected result:
If the version control tool can't be accessed, the project can be created and added to the project manager, then remind user the version control tool can't access

Actual result:
A warning dialog popup and project is created to disk, but not loaded to project manager

Comment:
SDKTestRound5; It should remind the user the Mercurial is not existed, and the new project is loaded to project manager.