Fixes Django issue deprecation issue

The current `settings.py` configuration in `LOGGING` produces a deprecation warning and raises `ValueError: Unable to configure handler 'azure'` changing the `instrumentation_key` to `connection_string`

## Using
- MacOS Ventura - 13.2
- Django 4.1.5
- Python 3.10.8

## To Replicate The Issue
Copy/Paste the code example in [Configure logging for Django applications](https://learn.microsoft.com/en-us/azure/azure-monitor/app/opencensus-python#configure-logging-for-django-applications)

This `settings.py` change becomes more similar to [Tracking Django Applications](https://learn.microsoft.com/en-us/azure/azure-monitor/app/opencensus-python-request#tracking-django-applications).

Author: kjaymiller

articles/azure-monitor/app/opencensus-python.md

@@ -154,7 +154,7 @@ LOGGING = {
         "azure": {
             "level": "DEBUG",
         "class": "opencensus.ext.azure.log_exporter.AzureLogHandler",
-            "instrumentation_key": "<your-ikey-here>",
+            "connection_string": "<your-application-insights-connection-string>",
          },
         "console": {
             "level": "DEBUG",