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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`
paginator = ddb_client.get_paginator('list_tables')
        pages = paginator.paginate(
            PaginationConfig={
                'PageSize': 100
            }
        )
        for page in pages:
            table_names = page['TableNames']
            if to_str(table_name) in table_names:
                return True
        return False
    def action_should_throttle(self, action, actions):
        throttled = ['%s.%s' % (ACTION_PREFIX, a) for a in actions]
        return action in throttled
    def should_throttle(self, action):
        rand = random.random()
        if (rand < config.DYNAMODB_READ_ERROR_PROBABILITY and
                self.action_should_throttle(action, READ_THROTTLED_ACTIONS)):
            return True
        elif (rand < config.DYNAMODB_WRITE_ERROR_PROBABILITY and
                self.action_should_throttle(action, WRITE_THROTTLED_ACTIONS)):
            return True
        elif (rand < config.DYNAMODB_ERROR_PROBABILITY and
                self.action_should_throttle(action, THROTTLED_ACTIONS)):
            return True
        else:
            return False
    def forward_request(self, method, path, data, headers):