can't goto a function after await keyword #543

Environment data

VS Code version: 1.19.1
Python Extension version: 0.9.1
Python Version: 3.6.4
OS and version: macOS 10.13.2

Actual behavior

Code like this

         await service.update_index(
            const.index_1212,
            const.doc_type,
            is_all)
        )
        future = service.update_index(
            const.index_1212,
            const.doc_type,
            is_all)
        

the first update_index can't use goto code navigation,but the second one can click and go to implement,thought they are the same python async function
the only diffence is the first one is after await keyword

Expected behavior

goto

Steps to reproduce:

code like upon

Logs

Output from Python output panel
None of output

Output from Console window (Help->Developer Tools menu)
None of output