Add fallback in case XDG_DATA_DIRS is not set
Without the change of this MR, I am getting:
$ ./local-music
Traceback (most recent call last):
File "./local-music", line 44, in <module>
os.environ["XDG_DATA_DIRS"]
File "/usr/lib/python3.6/os.py", line 669, in __getitem__
raise KeyError(key) from None
KeyError: 'XDG_DATA_DIRS'
because XDG_DATA_DIRS
is not defined. This MR fixes the issue.
Edited by Benoît Legat