Remove newrelic logging handler

It was introduced back in 2012, and is not used in the default
configuration.

lms/lib/newrelic_logging/__init__.py

-import newrelic.agent
-
-import logging
-
-
-class NewRelicHandler(logging.Handler):
-    def emit(self, record):
-        if record.exc_info is not None:
-            params = record.__dict__
-            params['log_message'] = record.getMessage()
-
-            newrelic.agent.record_exception(
-                *record.exc_info,
-                params=params
-            )

openedx/core/lib/logsettings.py

@@ -87,11 +87,6 @@ def get_logger_config(log_dir,
                 'filters': ['require_debug_false'],
                 'class': 'django.utils.log.AdminEmailHandler'
             },
-            'newrelic': {
-                'level': 'ERROR',
-                'class': 'lms.lib.newrelic_logging.NewRelicHandler',
-                'formatter': 'raw',
-            }
         },
         'loggers': {
             'tracking': {