C/C++ extension throws unhandled promise exceptions

[Radeonmann]

If a C or C++ file is already open when a workspace is opened, the C/C++ extension throws an unhandled promise exception because our extension did not provide the configuration in time.
Debug log example

Probably this is a timing issue of registering our extension and when we give the ready signal to the C/C++ extension.

The extension still works well after our extension finished activation, but for the end user it seems like something is not Ok: