Compilemessages builds translation files for projects in venv directory

[pierotofy]

But it really shouldn't.

Unfortunately this was fixed only in Django >= 3.

In the future, translate.py should be edited to use ignore_patterns:

for l in locales:
                    print("Building %s .po files into .mo" % l)
                    call_command('compilemessages', '--locale=%s' % l, ignore_patterns=["venv/*"]) # <-- here

Currently it just takes a bit longer to start dev mode.