improve error message when file path not found

[erwanp]

No description provided.

[erwanp]

@anandxkumar this may help with your error here.

Traceback (most recent call last):
  File "<ipython-input-4-48800e62a34c>", line 3, in <module>
    parfuncfmt='hapi',)
  File "/home/pipebomb/Desktop/radis/radis/lbl/loader.py", line 1201, in load_databank
    include_neighbouring_lines=include_neighbouring_lines,
  File "/home/pipebomb/Desktop/radis/radis/lbl/loader.py", line 1848, in _load_databank
    raise EmptyDatabaseError(msg)
EmptyDatabaseError: Reference databank has 0 lines in range 1997.50-2402.50cm-1 (5006.26-4162.33nm) Check your range !

Also happened when file paths were not found (therefore database was empty). Now you will get a DatabaseNotFound(FileNotFound) error.

[anandxkumar]

Hi @erwanp, it was indeed that error, the format of the file was different that's why it wasn't loading and was throwing that error, I just modified and it all loaded fine 👍 . Thanks for updating the error :)