Regression: C-c C-l keeps asking for a new session for different files within the same project

Even after starting a session called `project` for `project/Foo.hs`, C-c C-l keeps asking whether we should start a new project named `project` for each newly introduced file under the same project.

This broke only recently (unless it was done by design, in which case I would ask that we create a flag to enable/disable it).
