MRI pipeline does not start automatically even if auto-launch is turned on

[nicolasbrossard]

Even if auto-launch is turned on in the Config module, the MRI pipeline does not start automatically upon a successful scan upload. This was working in 20.1 but does not work in 20.2. The code that builds the command to run the MRI pipeline is wrong: it should use the values for the environment file path and prod file path that are stored in the Config, not some hard-coded paths.