az redis firewall-rules throwing an exception

```
az redis firewall-rules
The command failed with an unexpected error. Here is the traceback:
The operation 'azure.mgmt.redis.operations#FirewallRulesOperations.list_by_redis_resource' is invalid.
Traceback (most recent call last):
File "/home/paul/Code/frp/az-cli/.azdev/azdev-env/lib/python3.8/site-packages/azure/cli/core/commands/command_operation.py", line 61, in get_op_handler
handler = getattr(handler, part)
AttributeError: type object 'FirewallRulesOperations' has no attribute 'list_by_redis_resource'
```

Looks like the azure_mgmt_redis module has been updated, which removed the list_by_redis_resource method.