Error in get_project_info() in gdc.py when dataframe is empty

[arp95]

Hi,

When I run get_project_info(['test']), where the project id is not existing, in that case the get_project_info will have a empty dataframe and hence calling,

return df.set_index('id') results in an error.

To handle this case I have checked the dataframe is empty or not and then returned the dataframe accordingly. Please check the pull request.