Finetune loading projects for which no database is present works

[pverscha]

If a project is stored on the local filesystem that contains assays that have been analysed with a custom database that no longer exists, the application will automatically create this database and start building it in the background (even if the user did not request a re-analysis of the assay). This is very annoying if the user tries to view a project that was built by a large database and they don't want to reanalyse the assay (if they only want to view it, the underlying database should not be reconstructed).

Ideally, we would solve this by changing a couple of things:

• Instead of directly starting to build the missing database, we simply show a warning when the user is browsing a project that cannot immediately reanalyzed.