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# Type of request: This is a ...

[x] bug report
[ ] feature request

# Detailed description

When running with dynamodb errors set to 1.0 and performing basically any kind of request, I see the following in the console: 

```
localstack_main | 2021-01-22T22:14:37:WARNING:localstack.utils.server.http2_server: Error in proxy handler for request POST http://localhost:4566/: 'ProxyListenerDynamoDB' object has no attribute 'error_response_throughput' Traceback (most recent call last):
localstack_main |   File "/opt/code/localstack/localstack/utils/server/http2_server.py", line 107, in index
localstack_main |     raise result
localstack_main |   File "/opt/code/localstack/localstack/utils/bootstrap.py", line 581, in run
localstack_main |     result = self.func(self.params)
localstack_main |   File "/opt/code/localstack/localstack/utils/async_utils.py", line 28, in _run
localstack_main |     return fn(*args, **kwargs)
localstack_main |   File "/opt/code/localstack/localstack/services/generic_proxy.py", line 605, in handler
localstack_main |     response = modify_and_forward(method=method, path=path_with_params, data_bytes=data, headers=headers,
localstack_main |   File "/opt/code/localstack/localstack/services/generic_proxy.py", line 373, in modify_and_forward
localstack_main |     listener_result = listener.forward_request(method=method,
localstack_main |   File "/opt/code/localstack/localstack/services/edge.py", line 105, in forward_request
localstack_main |     return do_forward_request(api, method, path, data, headers, port=port)
localstack_main |   File "/opt/code/localstack/localstack/services/edge.py", line 116, in do_forward_request
localstack_main |     result = do_forward_request_inmem(api, method, path, data, headers, port=port)
localstack_main |   File "/opt/code/localstack/localstack/services/edge.py", line 136, in do_forward_request_inmem
localstack_main |     response = modify_and_forward(method=method, path=path, data_bytes=data, headers=headers,
localstack_main |   File "/opt/code/localstack/localstack/services/generic_proxy.py", line 373, in modify_and_forward
localstack_main |     listener_result = listener.forward_request(method=method,
localstack_main |   File "/opt/code/localstack/localstack/services/dynamodb/dynamodb_listener.py", line 97, in forward_request
localstack_main |     return self.error_response_throughput()
localstack_main | AttributeError: 'ProxyListenerDynamoDB' object has no attribute 'error_response_throughput'
```

which seems like a mistake. It looks like we get one of those for every request.

## Expected behavior

I wouldn't expect the console to print anything

# Steps to reproduce

I made #3501 to simplify reproduction. Basically just pull that, pull the latest docker image, run `./example/run.sh`.

## Command used to start LocalStack

`docker-compose up`
try:
                if has_event_sources_or_streams_enabled(data['TableName']):
                    ProxyListenerDynamoDB.thread_local.existing_item = find_existing_item(data)
            except Exception as e:
                if 'ResourceNotFoundException' in str(e):
                    return get_table_not_found_error()
                raise
            
            
            if ((data.get('ReturnValues') == 'ALL_OLD') or (not data.get('ReturnValues'))) \
                    and not data.get('ReturnConsumedCapacity'):
                data['ReturnConsumedCapacity'] = 'TOTAL'
                return Request(data=json.dumps(data), method=method, headers=headers)
        elif action == '%s.DescribeTable' % ACTION_PREFIX:
            
            if not self.table_exists(ddb_client, data['TableName']):
                return get_table_not_found_error()
        elif action == '%s.DeleteTable' % ACTION_PREFIX:
            
            if not self.table_exists(ddb_client, data['TableName']):
                return get_table_not_found_error()
        elif action == '%s.BatchWriteItem' % ACTION_PREFIX:
            existing_items = []
            for table_name in sorted(data['RequestItems'].keys()):
                for request in data['RequestItems'][table_name]:
                    for key in ['PutRequest', 'DeleteRequest']:
                        inner_request = request.get(key)
                        if inner_request:
                            existing_items.append(find_existing_item(inner_request, table_name))