chore: remove syslog handler from settings.py

[jennifer-richards]

System-level integration like this really needs to be in settings_local. This was causing problems when running in the dev environment.

To get the effect we want on ietfa, we should add the following to settings_local.py:

LOGGING["handlers"]["syslog"] = {
    'level': 'DEBUG',
    'class': 'logging.handlers.SysLogHandler',
    'facility': 'user',
    'formatter': 'plain',
    'address': '/dev/log',
}
LOGGING["loggers"]["datatracker"]["handlers"] = ["syslog"]
LOGGING["loggers"]["celery"]["handlers"] = ["syslog"]