Checkmk Werk 15653: agent_datadog: fix paging and handling of empty log message

ID: 15653 Title: agent_datadog: fix paging and handling of empty log message Component: Checks & agents Level: 1 Class: Bug fix Version: 2.3.0b1 Prior to this werk, the agent raised an error whenever the response did not contain a link to the next page and when a log contained an empty message. Both cases are now covered with this werk.