test: Fixed `AbstractConfigurationIT#testPutMessageInNewChatRoom()`
* In the case, that the request that adds a messag failed, the longly
process of creating a new chat-room, until it has the correct shard,
was unnecessarily repeated.
* Different workarounds have to be applied at the same time for the two
implementations:
** Because `ShardedChatHomeService` only throws a `ShardNotOwnedException`,
if the shard, that is picked by the strategy is not owned, the result
is retried until the requests succeeds by chance.
** The `KafkaChatHomeService` always creates the chat-room in the
partition, that is derived from the randomly picked id.
Hence, the loop, that is only left, if the randomly picked partition
matches the partition `2`, that the test-instance owns.
** Since `SimpleChatHomeService` does not know the concept of sharding
at all, the loop is also left, if no shard is set (shard is ``null``).